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EXTRACT FROM TABLE OF CONTENTS. 


ee Rel 3B I 


CHAPTER I. 


The Building and Finishing Woods of the United States.—Their char- 


acteristics, properties and uses. 
CHAPTER II. 


Wood Framing—Ordinary Construction.—Framing timber—Framing of 
wooden buildings—Framing of floors, supports for partitions, roof construc- 


tion—Superintendence. 
CHAPTER III. 


Sheathing, Windows and Outside Door Frames.—Sheathing of walls and 
roof—Cellar frames—Types of windows, construction of window frames in 


frame and brick walls, patent windows, casement windows, pivoted windows, 
bay windows—Sash, store fronts—Glass and glazing—Outside door frames. 


CHAPTER IV. 


Outside Finish, Gutters, Shingle Roofs.—Eaves and gable finish, gutters and 
‘conductors — Siding — Porches — Dormers—Shingling, flashing—Wood sky- 
lights. ‘ca 
CHAPTER V. 


Furring, Inside Finish, Doors, Stairs.—Furring for finish and plastering— 
Grounds and corner beads—Flooring—Doors and door frames—Casing of 
doors and windows—Paneling, beams, columns, stairs. 


CHAPTER VI. 


Builders’ Hardware,—Heavy hardware, bolts, nails, screws—Finishing hard- 
ware, butts, locks, knobs, bolts, window trimmings, trimmings for“blinds and 
shutters 

CHAPTER VII. 


Heavy Framing.—Framing of posts and girders, bracing, mill floors—Compound 
and trussed girders—Suspended floors, galleries. 


CHAPTER VIII. 
Specifications.—Carpenters’ work—Joiners’ Work—Hardware. 
| APPENDIX. 


Tables of Strength of wood and cast iron columns, wooden beams, maximum span 
for floor joists. mits ! 


ence Abb: 


TRUSSED ROOFS AND ROOF TRUSSES, 


(IN PREPARATION ) 
TABLE OF CONTENTS. 
INTRODUCTION. 


CHAPTER I. 


Definitions. Types of Wooden Trusses. 


CHAPTER II, 
Types of Steel Trusses, 


CHAPTER III, : 
Layout of Trussed Roofs. 


CHAPTER IV. 
Bracing of Roofs and Trusses. 


CHAPTER V. 
Open Timber Roofs and Church Roofs. 


CHAPTER VI. 
Vaulted and Domed Roofs and Ceilings. 


CHAPTER VII. 


Computing the Truss Loads. 


CHAPTER VIII, — 
Stress Diagrams for Vertical Loads. 


CHAPTER IX, 
Stress Diagrams for Wind and Snow. 


CHAPTER X, 
Stresses found by Computation. 


CHAPTER XI. 
Rules and Tables for Proportioning the members to the stresses, 


. CHAPTER XII. 
Joints in Wooden Trusses—Rules and Tables for. 


CHAPTER XIII. 
Joints in Steei Trusses. r 


CHAPTER XIV. 
Examples of trussed Reofs and Roof Trusses, 


BUILDING CONSTRUCTION 


AND SUPERINTENDENCE. 


Dye tee WD Dh RS Cob wPa. L:, 
ARCHITECT. 


Fellow American Institute of Architects. 


Author of “The Architects’ and Builders® Pocket Book.” 


Part I, 
SEVENTH EDITION 
MASONS’ WORK. 
260 //lustrations. 


oe 
anand 


New York: 
WILLIAM T. COMSTOCK, 


23 Warren Street. 


1905. 























COPYRIGHT, oe 
; B,7R. KIDDERS sis y ee 
iki ; : 1806. 3 : Lae — 





_ CopyRicH?s, ; + ena 
F, E, KIDDER. rcv rane 
' 1897. - 





oF . COPYRIGHT, 
; 5 F. E. KIDDER. : ¥ ¥ bts 
1898. 


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CoPpyYRIGHT, 
; * : FE E. ; KIDDER. ° 7 f 
: 1900. None 





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; F, E. KIDDER. © 
bi ) 4xh02: - 
COPYRIGHT, . ‘ i 
. F. E, KIDDER, : 
‘ 1903. is 





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| BE. KIDDER, | Pr 
| 1905. . 


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oie, 

53 

IA0S 

\, L PARCEL EA Glee 


HE primary object of the Author in preparing this volume has been to present 

to the Student, Architect and Builder a text book and guide to the materials 

used in Architectural Masonry and the most approved methods of doing the various 

kinds cf work, and incidentally to point out some of the ways in which such work 

should not be done, and the too frequent methods of slighting the work. That 

there is a demand for such a work has been evidenced to the Author by numerous 

inquiries from Architects and instructors in our Architectural schools, and also by 

the fact that there exists no similiar work describing American methods and 
materials. 

In describing methods of construction the Author has drawn largely from his own 
observation and experience as a practicing and consulting Architect in both the 
Eastern and Western States, although much assistance has been obtained from 
prominent Architects, who have cheerfully aided him by their advice and experience, 
and from the various books and publications to which references are made in the 
text; to all such the author gratefully acknowledges his indebtedness. 

To make the book convenient for practical use and ready reference, the various 
subjects have been paragraphed and numbered in bold-face type, and numerous cross 
references are made throughout the book. The table f con:ents shows the general 
scope of the book, the running title assisting in finding th» various parts, and a very 
full index makes everything in the book easy of access. The general character of 
the work is descriptive, and hence rules and formulee for strength and stability have, 
except in a few cases, been omitted ; such data being already fully presented in the 
Author’s ‘‘ Pocket Book” and other similar works. 

While intended principally as a book of instruction, there is much in the book 
that will be found valuable for reference, and of assistance in designing and laying 
out mason work, preparing the specifications, and in superintending the construction 
of the building, so that the Author hopes that even the experienced Architect will 
find it of assistance in his work. 

The enterprising builder, also, who wishes to thoroughly understand the mate- 
rials with which he has to deal, and the way in which they should be used, will 
find in this book much information that cannot be readily obtained elsewhere. 

To make the description as clear as possible many illustrations (mostly from orig- 
inal drawings) have been inserted, and an endeavor has been made to present only 
practical methods, and to favor only such materials as have been foun’ suitable for 


the purpose for which they are recommended, 


F,cE. KIDDER. 
Denver, Cola, June 1, 5890. 





TABLE OF CONTENTS. 


Thtrodnctionzc 7. es ae xe fees es Hehieer} enter ete esc = SRR as Oe 
Requirements for the Successful Practice of Architecture—Superintend- 
ence of Building Construction. 


CHAPTER I. 


Foundations on*FirmSoils.o0.. 22.25. cc... a. SAL ee Stevia te ere ecin 13 
Staking Out the Building. Foundations—light buildings—nature of 
soils, bearing power of soils, examples of actual loads, methods of testing. 
Designing the Foundations, proportioning the footings, examples, centre 
of pressure to coincide with centre of base. Superintendence. 


CHAPTER II. 


Foundations on Compressible Soils.. pis Sanna ke te Sila? ee ts ues! + Sk 
Pile Foundations—classes of piles, Serra i atee ae ringing, man- 
ner of driving, bearing power, actual loads on piles, cutting off and cap- 
ping. Grillage. Spread Foundations—concrete with tension bars— 
steel beam footings, method of calculating. Timber Footings, calcula- 
tions for—foundations for temporary buildings. Masonry Wells, examples 
of. Caissons, examples of. 


CHAPTER III. 


Masonry Footings and Foundation Walls.—Shoring and Under- 
PRM oars ee rene aed dale on Bais Sods Gh Kes a> 2h 0 bese see dace es 62 
Masonry Footings—concrete footings, stone footings, offsets, brick foot- 
ings. Inverted Arches, calculations for. Foundation Walls—bonding, fill- 
ing of voids, thickness of walls. Retaining Walls, proportions—Area 
Walls—Vault Walls—Filling in. Dampness in Cellar Walls. Window 
and Entrance Areas—Pavements. Cement Walks. Shoring—Needling— 
Underpinning—Bracing. 
CHAPTER. IV. 


DAMES a OMe SEO eNO ALS cre de fines oss sp alee vy dm «vies conse sts wees 93 
Lime—characteristics of, slaking and mixing. Sand. White and Colored 
Mortars. Durability of Lime Mortar. Hydraulic Lime—Pozzuolanas. 
Natural Cements—distribution of, analysis of, characteristics, testing— 
Roman Cement. Portland Cement—American Cement—testing, strength, 
specifications for. Cement Mortars—use, mixing, proportions—Grout. 
Data for Estimating Cost of Mortar. Strength of Mortar. Freezing of 
Mortar. Concrete—mixing, proportions, depositing, data for estimating. 
Mortar Colors and Stains—mixing. 


6 TABLE OF CONTENTS. 


CHAPTER V. 

sg Stonesiog- oe ste eo eae ee em nen inlet Pon 9 eo 124 
Granites—characteristics of, distribution of. Limestone—characteristics of, 
description of principal varieties. _Marble—Description of American Mar- 
bles—Onyx Marbles. Sandstones—characteristics of, description of well- 
known varieties. Lava Stone. Slate—qualities and distribution of. 
Selection of Building Stones—method of finishing, strength. Testing of 
Building Stones—Seasoning of Stone—Protection and Preservation of 
Stonework. 

CHAPTER VI 

Cut. Stonework, 9c F5 5. eck pene sects pen it eg ia eae 150 
Rubble Work—Ashlar. Stonecutting and Finishing—tools, kinds of fin- 
ish. Laying Out—trimmings, relieving and supporting lintels, sills, arches, 
label mouldings, relieving beams over arches, elliptical arches, flat arches, 
rubble arches—Centres. Miscellaneous trimmings—columns, copings, 
stone steps and stairs. Slip Joints. Bond Stones and Templates. Set- 
ting Stonework—protecting, pointing, cleaning down. Strength of Stone 
Masonry—lintels, columns. Measurement of Stonework. Superintendence 
of Cut Stonework. 

CHAPTER VIL. 

Brick workers 062 scsicas © ohegl visemes # 9a) (ct cs Wits alcdera aia siete een reer 189 
Bricks—composition, manufacture, glazed and enameled, paving, fire’ 
bricks. Classes of Building Brick—common brick, pressed brick. Color 
of bricks, size and weight. Requisites of good brick—strength. Brick- 
work—thickness of mortar joints, laying brick, wetting brick, laying in 
freezing weather. Ornamental Brickwork—belt courses, cornices, surface 
patterns. Construction of Walls—bond, anchoring the wall, corbeling for 
floor joist, bonding at angles, openings, joining new walls to old. Thick- 
ness of Walls—party walls. Wood in Walls—cracks in walls. Damp- 
proof Courses. Hollow Walls—methods of construction, bonding. Brick 
Veneer Construction. Details—brick arches, vaults, chimneys, fireplaces, 
brick nogging. Cleaning Down—efflorescence—damp-proofing. Crushing 
Strength of Brickwork. Measurement of Brickwork. Superintendence. 


CHAPTER VIiIT. 


Architectural. Terra Cotta. <2. 5.2 gt tee eto eaten met aes 249 
Composition and manufacture, color, use, durability, inspection. Laying 
Out. Examples of Construction. Setting and Pointing—cost, weight and 
strength, protection. 

CHAPTER IX. 

Fireproofing.. Rr rye bore Oe rik: PEt PERT ETE PL 258 
\icrernretnenee ioe porous tiling, concretes. Floor Construction— 
side-method arches, end-method arches, combination of side and end 
methods. Depth, Weight and Strength of Flat Tile Arches—manner of 
setting—protection. Floor and Ceiling Finish. Segmental Tile Arches. 
Guastavino Arch. The ‘‘ Fawcett” Floor. Concrete and Metal Floors— 
the Ransome & Smith floor—the Lee tension member floor—the Metropol- 
itan floor—the Roebling floor—the Columbian floor. Actual Weight of 
Fireproof Floors ; selection of asystem., Fireproof Roofs—flat roofs, pitch 


TABLE OF CONTENTS. « 


and mansard roofs. Ceilings. Girder and Column Casings. Partitions— 
thin partitions. Wall Furring. 


CHAPTER X. 


Iron and Steel Supports for Mason Work.—Skeleton Construction. 301 
Girders and Lintels—cast iron lintels, cast iron arch girders. Supports for 
Bay Windows. Wall Supports in Skeleton Construction—spandrel sup- 
ports, bay window supports. Miscellaneous Ironwork—bearing plates, 
skewbacks, shutter eyes, door guards, chimney caps, ladders, coal hole 


covers. 
CHAPTER XI. 


PERCHA PAO ET SASCOLIND Be coe trate tore wane aie vine vies Sc welts Hae tates eins 318 
Lathing—wood lathing, metal lathing, wire lath, furring for wire lath, 
stiffened wire lath—expanded metal and perforated laths. Plaster Boards. 
Where Metal Lathing should be Used. Plastering—materials for, mixing, 
machine-made mortar—proportions of materials—Putting On the Plaster. 
Hard Wall Plasters—nature of, advantages, how used and sold. Stucco 
Work—Keene’s cement, scagliola, fibrous plaster. External Plastering— 
stucco, staff. Whitewashing. Lath and Plaster in Fireproof Construction— 
thin partitions. Plastering Superintendence. Measuring Plasterers’ Work. 


Cost. 
CHAPTER XII. 


Concrete: Guiding CONStriiCtiOli, nr toa etalk oes ica dois dhe Sian ciersuie os 357 
Use of Concrete for Buildings. Examples of. Notable Concrete Buildings 
in the United States. Details of Construction—surface finish, making the 
concrete, expansion and contraction. Fireproof Vaults. Sidewalk Con- 


struction. 
CHAPTERAXITE 


SRECIICALONS mee sae en cee ie ene ad nop ds nh dvs aoe fone sane 370 
Introduction. General Conditions. Excavating and Grading. Piling. 
Concrete Footings. Stonework—footings, foundation walls, external 
stone walls, cut stonework. Brickwork. Laying Masonry in Freezing 
Weather. Fireproofing—hollow tile system. Architectural Terra Cotta. 
Lathing and Plastering—ordinary work, hard wall plasters, wire lathing 
and furring, thin partitions. 


PETIOLATE ee Te Ne ce Fale ty paciaa caves besecnsee s 391 
Table A. Weight, Crushing Strength and Ratio of Absorption of Build- 
ing Stones. 
Table B. Chemical Composition of Building Stones. 
Table C. List of Prominent Stone Buildings. 
Table D. Effect of Heat on Various Stones. 
Table E. Actual Crushing Strength of Brick Piers. 
Table F. Safe Working Loads for Masonry. 
Table G. Properties of Timber, Stones, Iron and Steel. 
Making Cellars Wa‘erproof. 


[OVER] 


8 TABLE OF CONTENTS. 


ADDITIONS TO SECOND EDITION. 


Brick: Fireplaces(\s-. ones sc'essg ee OF passe dene eae Rosen ain’ a ays Sop gies Th on eaee 
Brick Spiral Stairs, 2254.25 7. wee vide cewhle one Sede Sawin eis tein aieiab Cee aes ys afew deere 2425 
Expanded Metal Furring in Fireproof Buildings.............ccecesecceees 350a 
Door and Window Frames in Thin Fireproof Partitions...........0.e.se08. 351 
Colored Sand. }inish so. 3. = sth ae oeks. oe pry wba wk aiclalstel a statete aie viele aol'ale 356 
Other Uses for Concrete Construction........ Petes etata So ope ecnas ativace de 62 G00 
Stain and Damp-proofing—Antihydrine.. Soleese an muse a daisinete a ais 403 
Roebling Fireproof Floor, Weight and Sircheah ee os. aise eae Sainers elacie «vem ore SAO4 
Expanded Metal Systems of Floor Construction. .......sesceeecccccccccccess 406 
‘Ferra Blanca Fireproof (Piling. citicake as emeadess acs ems oe ccc secee Ss a eain « 408 


Pelton’s System of: Released Ashlarii 0% cx cases ac'eiscue sceeeb we cient ccs aro 


INTRODUCTION. 


design, but also a thorough knowledge of building construction in all its 
branches, at least so far as to know how the work should be done, and 
conscientious and painstaking supervision of the work. 

Without a knowledge of the best methods of performing building operations, 
and of the materials that should be used, it is impossible for the architect to pre- 
pare his specifications intelligently, and so as to secure the kind of work he wishes 
done ; and upon the thoroughness with which the specifications are prepared 
depends in a great measure the satisfactory execution of the work. 

The position occupied by the architect as a judge or referee between the 
owner and contractor also makes it necessary that he should be able to show such 
thorough familiarity with common practice as will command the respect of both. 
Workmen soon discover whether the superintendent is familiar with the difference 
between good and bad work, and if they find him wanting they are quite sure to 
take advantage of his lack of knowledge. 

After the plans and specifications have been prepared with the utmost care, 
accidents, failures and bad work are quite sure to occur unless the building opera- 
tions are carefully and intelligently supervised. In fact, probably move failures in 
buildings occur from the use of poor materials and bad workmanship than from 
faults in the plans. 

While it is impossible for one to acquire a thorough knowledge of building 
construction from books alone, it is necessary, for the young architect, especially, 
to depend upon technical books to a large extent for his knowledge of how work 
should be done, and of what materials are best suited for certain purposes, and 
how they should be used. As a substitute for his lack of knowledge, he must rely 
largely upon knowledge gained through the experience of others, oftentimes at 
great cost. — 

In these books the author has endeavored to describe all the ordinary building 
operations in such a way that they may be easily understood, and to point out the 
defects often met with in building materials and construction, and to indicate in a 
measure how they may be avoided. 

To get along well with contractors and workmen the architect must feel sure 
that his opinions and decisions are correct, and stick to them. Of course one can 


alies successful practice of Architecture requires not only ability to draw and 


often learn much from practical builders, but unless he is already somewhat 
informed upon the subject he is often likely to be imposed upon. In fact, one of 
the greatest troubles of young architects in superintending their buildings, lies in 





CHAPTER I. 


FOUNDATIONS ON FIRM SOILS. 





STAKING OUT THE BUILDING. 


I. Except for city blocks, staking out the building is gen- 
erally left to the contractor, but the superintendent should see 
that it is carefully done, and very often he is expected or called 
upon to assist in running the lines. The principal corners of 
the building should first be carefully located by small stakes driven 
into the ground with a nail or tack marking the exact intersec- 
tion of the lines. The lines should then be marked on déatter 
boards, put up as shown in Fig. 1. Three large stakes (2x4 or 4x4) 
are firmly driven or set 
in the ground at each cor- 
ner of the building and 
from six to ten feet from 
the line of the building, 
according to the nature 
of the ground, and fence 
boards nailed horizon- 
tally from the corner post 
to each of the other two 
posts. These boards 
should be long enough 
so that both the inside 
and outside lines of the 
foundation walls may be 
marked on them. ‘The 
stakes should also be 
braced from the bcttom 
of the corner stake to the 
top of the others. This 
makes a firm support for 
the lines and one that need not be moved until the walls are up for 
the first floor. These boards have the great advantage over single 
stakes that they are more permanent, and that all projections of the 
walls, such as footings, basement wall and first story wall, can readily 





14 BUILDING CONSTRUCTION. 


be marked on them. It is a good idea to indicate the ashlar line by 
a saw mark, the basement line by a nail and the footings by a notch, 
then no mistake can be made by the workmen. If the top of all the 
horizontal boards are kept on a level it assists a great deal in getting 
levels for the excavating, etc. 

The superintendent will be expected to furnish the contractor with 
a bench mark, from which he can get the level for his footings, floor 
joist, etc. This mark should be put on some permanent object, 
where it can be referred to after the first floor joists areon. In giving 
‘such data to the contractor the superintendent must be very careful, 
as he can be held responsible for any loss resulting from errors which 
he may make. It is a very safe and good rule to. give as few lines, 
data or measurements as possible to contractors, requiring them to 
lay out all the work themselves and to be alone responsible for the 
accuracy of their work. 

2. Diagonals.—After the batter boards are in place and properly 
marked, the superintendent should require the contractor or his fore- 
man to stretch the main lines of the building, and the superintendent 
should carefully measure the diagonals, as A B and C D, Fig 1, with 
a steel tape ; if they are not exactly of the same length the lines are 
not at right angles with each other and: should be squared until the 
diagonals are of equal length. 

On fairly leyel ground a building may be accurately laid out by 
means of a steel tape, using multiples of 3, 4 and 5 for the sides and 
hypothenuse of a right angle triangle. The larger the triangle the 

“more accurate will be the work. 

3. For buildings which are built out to the street line the lines of 
the lot should be-given by a surveyor employed by the owner, and 
should be fixed by long iron pins driven into the street, or by lines 
cut on the curbstone across the street. In building close to the 
party lines of a lot it is, of course, of great importance that the build- 
ing does not encroach upon the adjacent lot, and to prevent this it is 
always well to set back one inch from the line, thus allowing for any 
irregularities or projections in’ the wall. 


FOUNDATIONS—LIGHT BUILDINGS. 


4. Nature of Soils.—The architect should in all cases make 
every endeavor to discover the nature of the soil upon which his 
building is to be built before he makes his foundation plan. For 
most buildings, a sufficient idea of the nature of the soil may be 
gained by inquiry amongst builders who have put up buildings on the 


FOUNDATIONS ON FIRM SOILS. 15 


adjacent lots. Many soils, however, vary greatly, even in a distance 
of 100 feet, owing to the strata having a decided dip, and on all such 
soils much trouble and annoyance may often be saved by having bor- 
ings made with a post auger, showing the composition of the soil at 
different strata. If two borings made on different sides of the site 
show about the same depth and character of soil it may be assumed 
that other borings would give the same result, but if the soil brought 
up by the first two borings show a difference in the character of the 
soil, or indicate that the strata have a decided pitch, then borings 
should be made all around the foundations. 

For ordinary buildings borings to the depth of 8 or 1o feet are 
generally sufficient, although a 6 or 8-inch auger may be driven to 
the depth of 20 or 25 feet by two men using a lever. In soft soils a 
pipe must first be sunk and the auger worked inside of it. A smaller 
auger will answer in such cases. 

For dwellings built on sand, gravel, clay or rock, an examination 
of the bottom of the trenches, and a few tests with an ordinary crow- 
bar or post auger, will generally be all that is necessary. 

When borings are deemed necessary the owner should be advised 
of the fact, and his authority obtained for incurring the expense, 
which should be defrayed by him. 

5. Different soils have not only different bearing or sustaining 
powers, but also various peculiarities which must be thoroughly un- 
derstood and considered when designing the foundation. _ 

An architect who, as a draughtsman, has had several years’ expe- 
rience in one locality before practicing for himself, will naturally 
have become acquainted with the peculiarities of the soil in that 
vicinity ; but should his practice extend beyond his own city he 
should carefully study the nature and peculiarities of the soil in each 
different locality where he may have work, and also obtain all the 
information possible, bearing on the subject, from local builders, as 
otherwise he may fall into serious trouble. 

No part of a building is more important than the foundation, and 
more cracks and failures in buildings will be found to result from 
defective foundations than from any other cause; and for any such 
defects, resulting from the neglect of usual or necessary precautions, 
the architect is responsible to the owner, besides the damage which 
inevitably results to his own reputation. : 

The following observations are intended as a general guide in pre- 
paring foundations on different soils, although they should be sup- 
plemented by the experience of local builders wherever possible. 


16 BULIEDING CONSTARECTION, 


6. Rock.—Rock, when it extends under the entire site of the 
_building, makes one of the best foundation beds, as even the softest 
rocks will safely carry more weight than is likely to come upon them. 

The principal trouble met with in building on rock is the presence 
of water. As the surface water cannot readily penetrate the rock, it 
collects on top of the ledge and in the trenches, so that some arrange- 
ment for draining away the water should be provided. If the ledge 
falls off to one side, a tile or stone drain may be built from the low- 
est point of the footings to near the surface on the slope. If ina 
sewer district, the water may be drained into the sewer, using proper 
precautions for trapping and ventilation. If there is no sewer and 
the rock does not fall off, a pit should be excavated at the lowest 
part of the cellar to collect the seepage, and an automatic arrange- 
meut provided for raising the water into a drain laid above the sur- 
‘ face of the rock. 

To prepare the rock for the footings, the loose and decayed por- 
tions should be cut away and dressed to a level surface. If the sur- 
face of the rock dips, or is irregular in its contour, the portion under 
the footings should be cut to level planes or steps, as shown in 
Fig. 2.. In no case should the footings of a wall rest on an inclined 


bed. 





7. If there are fissures or holes in the rock, they should be filled 
with concrete, well rammed; or, if the fissure be very deep, it may be 
spanned by an arch of brick or stone. In building on rock it is 
very desirable that the footings shall be nearly level all around the 
building, and whenever this is not the case the portions of the foun- 
dation which start at the lower level should be laid in cement mortar 
and with close joints, otherwise the foundations will settle unequally 
and cause cracks to appear above. 

8. Should it be absolutely necessary to build partly on rock and 
partly on soil, the footings on the soil should be made very wide, so 
that the settlement will be reduced toa minimum. The footings rest- 
ing on the rock will not settle, and the least settlement in those 
resting on the soil will be sure to produce a crack in the superstruc- 
ture, and perhaps do other damage. 

Building on such a foundation bed is very risky at best, and 
should always be avoided if possible. 


FOUNDATIONS ON FIRM SOILS. 17 


9g. Clay.—This soil is found in every condition, varying from 
slate or shale, which will support any load that can come upon it, to 
a soft, damp material, which will squeeze out in every direction when 
a moderately heavy pressure is brought upon it. 

Ordinary clay soils, however, when they can be kept dry, will carry 
any usual load without trouble, but as a rule clay soils give more 
trouble than either sand, gravel or stone. 

In the first place, the top of the footings must be carried below the 
frost line to prevent heaving, and for the same reason the outside 
face of the wall should be built with a slight batter and perfectly 
smooth. The frost line varies with different localities, attaining a 
depth of six feet in some of the very Northern States, although 
between three and four feet is the usual depth in the so-called 
Northern States. The effect of freezing and thawing on clay soils is 
very much greater than on other soils. 

The surface of the ground around the building should be graded 
so that the rain water will run away from the building, and in most 
clays subsoil drains are necessary. When the clay occurs in inclined 
layers, great care must be exercised to prevent it from sliding, and 
when building on a side hill the utmost precautions must be taken to 
exclude water from the soil, for if the clay becomes wet the pressure 
of the walls may cause it to ooze from under the footings. The erec- 
tion of very heavy buildings in such locations must be considered 
hazardous, even when every precaution is taken. 

Should it be necessary to carry a portion of the foundations to a 
greater depth than the rest, the lower portion of the walls should be 
built as described in Section 7, and care must be taken to prevent the 
upper part of the bed from slipping. Wherever possible, the footings 
should be carried all around the building at the same level. 

10. In Eastern Maine, where the soil is a heavy blue clay, and 
freezes to the depth of four feet, it is customary to build the founda- 
tion walls as shown in Fig. 3, the footings being laid dry, to act asa 
drain, and the bottom of the trench being slightly inclined to one 
corner, from whence a drain is carried to take away the water. The 
_ portion of the trench outside of the wall is also filled with broken 
stone or gravel to prevent the clay from freezing to the side of the 
wall. In the better class of work the outside of the wall is plastered 
smooth with cement. Sometimes a tile drain is laid just outside and 
a little below the footings. 

II. If the clay contains coarse sand or gravel its supporting power 
is increased, and it is less liable to slide or 00ze away. 


18 BUILDING CONSTRUGTLIIGN,. 


In Colorado the top soil consists principally of clay, mixed with 
fine sand, and as long as it is kept dry will sustain. a great load 
without settlement. As soon as the soil becomes wet, however, it 
turns into a soft mud, which is very compressible and treacherous. 
For this reason the footings of heavy buildings are carried through 
the clay to the sand below. A peculiarity of this soil is that, 
although it freezes, it has never been known to heave, so that two- 
story buildings are often built directly on top of the ground, and as 
jong as water 1s kept away from the walls no injury results. 


12. Gravel.—This material gives less trouble than any other as a 

foundation bed. It does not settle under any ordinary loads, and 
will safely carry the heaviest 
of buildings if the footings » 
are properly proportioned. 
It is not affected by water, 
provided it is confined lat- 
erally, so that the sand and 
fine gravel cannot wash out. 
This soil is also not greatly 
affected by frost. 

13. Sand.—This mate- 
rial also makes an excellent 
foundation bed when con- 
fined laterally, and is prac- 
tically incompressible, as 
clean river sand compacted 

. In atrench has been known 
to support roo tons to the 
square foot. 

gy 3 . As long as the sand is 

PS Orne. tase confined a all sides, and 
Ly one. 

the footings are all on the 

Fig. 3. same level, no trouble what- 

ever will be encountered, 

unless it be in the caving of the banks in making the excavations. 
Should the cellar be excavated to different levels, however, sufficient 
retaining walls must be erected where the depth changes to prevent 
the sand of the upper level from being forced out from under the 
footings, and precautions should be taken in such a case to keep 
water from penetrating under the upper footings. 





FOUNDATIONS ON FIRM SOJLS. 19 


14. Loam and Made Land.—No foundation should stazt on 
loam (soil containing vegetable matter), or on land that has been 
made or filled in, unless, indeed, the filling consist of clean beach 
sand, which, when settled with water, may be consideréd equal to the 
natural soil. 

Loam should always be penetrated to the firm soil beneath, and 
when the made land or filling overlies a firm earth, the footings 
should be carried to the natural soil. When the filled land is always 
wet, as on the coast or the borders of a lake, piles may be used, ex- 
tending into the firm earth, and the tops cut off below low water 
mark; but piles should never be used where it is not certain that they 
will be always wet. 

15. Mud and Silt.—Under this heading may be included al] 
marshy or compressible soils which are usually saturated with water. 

Foundations on such soils are generally laid in one of the three 
following ways: 1. By driving piles on which the footings are sup- 
ported. 2. By spreading the footings either by wooden timbers or 
steel beams so as to distribute the weight over a large area. 3. By 
sinking caissons or steel wells, filled with masonry, to hard pan. As 
all of these methods are more or less complicated they. will be 
described in Chapter II. 

16. Bearing Power of Soils.—The best method of determin- 
ing the load which a particular soil will bear is by direct experiment; 
but good judgment, aided by a careful examination of the soil—par- 
ticularly of its compactness and the amount of water it contains—in 
conjunction with the following table, will enable one to determine 
with reasonable accuracy its probable supporting power. A mean of 
the values given below may be considered safe for good examples of 
the kinds of soils quoted: 

TABLE I.—BEARING POWER OF SOILS. 





BEARING POWER 
IN TONS PER 


KIND OF MATERIAL. SQUARE FOOT. * 














MIN. MAX 

OCI BHAT ct G ch ttiste cretenre Miorste fein hc ties e wateieln cis wicitate bba <erere's 25 30 
IOC SOL ta ree eas cote Oe wicie cecleisicta ie nli'e whale SOS Balclae's @ 5 10 
Clayon thick beds; always dry. iets nceawcs ie ees eex ec vive ne els 4 6 
Clay.on thick. beds cmoderately dryer ese. sissies cerctse ett © a 4 
Ace SOE Ls teks yas s coats fate oo. wo caemenn sein, ato aikte Sine eeua were 6.6. os I 2 
Gravel and coarse sand, well cemented...........ecece0% Rees 8 10 
Spana, compact and well ‘cemented ©. 4. ssa. «+ « + «statidiiacatwaing « «> 4 6 
See CE GPO AICI Y. Gs siaits on cies Cate wine Cerna ein 6 ottie whee ste vide n ¢ 2 4 
SPICE SATION OUUVIAL SOUS, CLCY is acs coerce niece ais se ces Sieve sis 4 0.5 I 


* Ira O. Baker, C. E., in ‘‘ Treatise on Masonry Construction.”’ 


20 BUILDING, CONSLROCLI ON, 


Should it be desirable to exceed the maximum loads here given, or 
should there be any doubt of the bearing capacity of the soil or lack 
of precedent, tests should be made on the bottom of the trenches in 
several places to determine the actual load required to produce set- 
tlement, as described in Section 18. 

17. Examples of Actual Loads and Tests. 

On Clay.—T7%e Capitol at Albany, N. Y., rests on blue clay containing from 
60 to go per cent. of alumina, the remainder being fine sand, and containing 40 per 
cent. of water on an average. The safe load was taken at 2 tons per square foot. 
A load of 5.9 tons applied on a surface 1 foot square produced an uplift of the sur- 
rounding earth. 

The Congressional Library at Washington, D. C., rests on yellow clay mixed 
with sand. It was found that it required about 1344 tons per square foot to pro- 
duce settlement, and the footings were proportioned for a maximum pressure of 
216 tons 

A hard indurated clay, containing lime, under the piers of a bridge across the 
Ohio River, at Point Pleasant, W. Va., carries approximately 21 tons per square foot. 

Sand.—‘‘ In an experiment in France, clean river sand compacted in a trench 
supported 100 tons per square foot. 

‘‘The piers of the Cincinnati suspension bridge are founded on a bed of coarse 
gravel 12 feet below.water; the maximum pressure is 4 tons per square foot. 

‘«The piers of the Brooklyn suspension bridge are founded 44 feet below the bed 
of the river, upon a layer of sand 2 feet thick, resting upon bed rock; the maximum 
pressure is about 514 tons per square foot.” * 

18. Methods of Testing.—Probably the easiest method of 
determining the bearing power of the foundation bed is by means of 
a platform from 3 to 4 feet square, having four legs, each 6 inches 
square. ‘The platform should be set on the bottom of the trench, 
which should be carefully leveled to receive the legs. A level should 
then be taken from a stake or other bench mark not liable to be dis- 
turbed to each of the four corners of the platform, and the platform 
then loaded with dry sand, brick, stone or pig iron, as may be most 
convenient. ‘The load should be put on gradually, and frequent lev- 
els taken until a sinkage is shown. From one-fifth to one-half of 
the load required to produce settlement is generally adopted for the 
safe load, according to circumstances. In testing the ground under 
the Congressional Library a traveling car was used, having four cast 
iron pedestals, each measuring 1 square foot at the base and set 4 
feet apart each way. The car was made to move along the trenches, 
and halted at intervals in such a way as to bring the whole weight of 
the car and its load upon the pedestals which rested on the bottom 
of the trench. In this case the car was loaded with pig lead. 


*Ira O. Baker, C. E. American Architect, November 3, 1888. 


FOUNDATIONS ON FIRM SOILS. a2 


The only objection to this method is that if the legs do not settle 
evenly it is impossible to tell just what the pressure on the lowest 
corner amounts to, but it would not be safe to consider it as more 
than one-fourth of the whole load. 

19. In testing the soil under the State Capitol at Albany, N. Y., 
the load was placed on a mast 12 inches square, held vertical by 
guys, with a cross frame to hold the weights. The bottom of the 
mast was set in a hole 3 feet deep, 18 inches square at the top and 14 
inches at the bottom. Small stakes were driven into the ground in 
lines radiating from the centre of the hole, the tops being brought 
exactly to the same level, so that any change in the surface of the 
ground could readily be detected and measured by means of a 
straight-edge. In this case no change in the surface of the ground 
was noticed until the load reached 5.9 tons, when an uplift of the 
surrounding ground was noticed. 


DESIGNING THE FOUNDATIONS. 


20. Knowing the character and supporting power of the soil on 
which he is to build, the architect is prepared to design his founda- 
tion plans, but in no case should this be done when the preceding 
information is wanting. 

In designing the foundations the first point to be settled will be the 
depth of the foundations; second, whether they shall be built in piers 
or in a continuous wall; and, third, the width of the foundations. 

21. Depth.—For isolated buildings on firm soil the depth of the 
foundations will generally be determined by the depth of the base- 
ment or by the frost line. Even where there is no frost, and the 
ground is firm, the footings should be carried at least 2 feet below 
the surface of the ground, so as to be below the action of the surface 
water. In very few soils, however, is it safe to start the foundations 
at a less depth than 5 feet. (See Section 9.) 

22. The depth of the foundations for czty dbuz/dings, built near the 
lot line, should be governed by the local laws bearing on the subject, 
the character of the soil, and probable future action of the owners of 
the adjoining property. 

In most cities the law provides that the owner of any lot excavat- 
ing below a certain depth (usually about ro feet) shall protect the 
wall of the adjoining property at his own expense, but if he does not 
excavate below that depth (10 feet) then the adjoining owners must 
themselves protect their property from falling in. 

It is, therefore, always wise to provide against any such future 


22 BUILDING CONSTRUCTION. 


expense and trouble by carrying the footings—at least those of the 
side walls—to the prescribed limit, above which the owner will be 
responsible, even if the requirements of the soil or building do not 
necessitate 1t. This precaution is especially important when the 
building is erected on sand. 

23. Continuous Foundations vs. Piers.—It has been found 
that when heavy buildings are to be erected on soft or compressible 
soils, greater security from settlement may be obtained by dividing 
the foundation into isolated piers, as described in Chapter II. 

When building on firm soils, however, no advantage is gained by 
pursuing this method, unless the walls of the building are themselves 
composed of piers with thin curtain walls between, in which case the 
foundations under the piers and walls should be built of different 
widths, and not bonded together, as described in Section 30. 

When the walls are continuous, however, and of the same thickness 
throughout, the foundation should be continuous. The architect 
should constantly bear in mind that in all kinds of building construc- 
tion the simplest methods are almost always the best, and compli- 
cated arrange . ents and the use of iron, etc, in foundations should 
be avoided, at least on firm soils. 

24. Proportioning the Footings. a neihe the foundations 
are continuous or divided into piers the area of the footings should 
be carefully proportioned to the weight which they support and the bear- 
ing power of the soil. ‘The former is perhaps the most important of 
all considerations in designing the footings. While the safe bearing 
power of the soil ought not to be exceeded, this is, on most soils, not 
of so much importance as the proportioning of the footings, so that 
the pressure on the soil from every square foot of the footings will be- 
the same. If this condition were always obtained there would be few 
cracks in the mason work of buildings, as such cracks are caused not 
by a uniform settlement of an inch or two, which with most build- 
ings would not be noticed, but by wzegual settlement. 

25. In proportioning the area of the footings the architect should 
carefully compute the weights coming upon each pier, and the weight 
of and loads supported by the walls, and record the same in a mem- 
orandum book for reference. 

He should then decide, by means of Section 16 and from an exam- 
ination of the ground, or, if necessary, from actual tests, the bearing 
weight which it appears advisable to assume, and dividing the load 
on the various footings by this assumed carrying load will give the 
proper area of the footings. 


FOUNDATIONS ON FIRM SOILS. . 23 


The pressure under piers supporting a tier of iron columns may be 
made 10 per cent, more than under a brick wall, so that the pier may 
settle a little more to allow for the compression in the joints of the 
mason work. 

26. /7 computing the weight to be supported by the footings the 
live (or movable) load and dead load should be computed separately. 
In building on any compact soil the object in carefully proportioning 
the footings, as has been stated, is not so much to prevent any set- 
tling of the building as a whole, but to provide for a uniform settling 
of all portions of the building, so that the floors may remain level and 
no cracks be developed in the walls. In order to secure this, it is 
necessary that the loads for which the footings are proportioned 
should be as near the actual conditions as possible.* Thus the dead 
load under the walls of a five-story building would be a considerable 
item, while the dead load under a tier of iron columns would be 
much less in proportion to the floor area supported, and, as the dead 
load is always constant and the live load may vary greatly, only the 
amount of live load that will probably be supported by the footings 
most of the time should be considered. 


for warehouses, stores, etc., about 50 per cent. of the live load for 
which the floor beams are proportioned should be added to the dead 
load supported on the footings. 

Lor office buildings, hotels, etc., the weight of the people who may 
occupy them should be neglected altogether in proportioning the 
footings, and only about 15 pounds per square foot of floor allowed 
to cover the weight of furniture, safes, books, etc. [Actual statistics 
show that the permanent average loads in such buildings do not exceed 
the above limit. | 

For theatres and similar buildings some allowance should probably 
be made for the weight of people, the actual amount depending upon 
the arrangement of the plan and the character of the soil. 


Almost any soil, after it has been compacted by the dead weight of 
a building, will carry a shifting load of people without further settle- 
ment, while if the footings were computed to carry the full live loads 
for which the floor beams were designed, it would be found that 
when the building was finished the actual loads on the footings under 
the walls would be much greater than under the interior piers, and 
if the ground had settled at all during building, the probabilities 





* Foundations shall be proportioned to the actual average loads they will have to carry in the 
completed and occupied building, and not to theoretical or occasional loads.—Chicago Butlding 
Ordinance. 


£4. BOILDING CONSTRUCTION, 
would be that the floors of the building would be higher in tne cen- 
tre than at the walls. 

27. Example 7—We will suppose that a six-story and basement 
warehouse is to be erected on an ordinary sand and gravel founda- 
tion. The building will be 50 feet wide, with two longitudinal rows 
of columns and girders. What should be the width of the footings 
under the walls and columns? 

Answer.—F or the load on one lineal foot of footing under the side 
walls we will have about 140 cubic feet of brick and stone work, 
weighing about 17,000 pounds.* One lineal foot of wall will also 
support about 8 square feet of each floor and the roof. We will 
assume that the floors are of iron beams and terra cotta tile, with con- 
crete filling, weighing altogether 75 pounds to the square foot, and 
the roof of the same material, weighing 60 pounds. Then the dead 
load from the six floors and roof would amount to 4,080 pounds. 
The first, second and third floors are intended to support 150 pounds 
to the square foot, and those above 100 pounds per square foot. The 
possible weight of snow on the roof we will not take into account. 
There might then be a possible live load on the footing of 6,000 
pounds, but as it is improbable that each floor will be entirely loaded 
at the same time, and as some space must be reserved for passages, 
etc., the actual live load would probably not exceed for any length of 
time 50 per cent. of the assumed load, or 3,000 pounds. Adding 
these three loads together (the wall, floors and live load) we have 
24,080 pounds as the load on one lineal foot of footing. We will 
allow 6,000 pounds (3 tons) for the bearing power of the soil, and 
dividing the load by 6,000 we have 4 feet as the required width of 
the footing. ‘The load on the footings under the columns will con- 
sist only of the weight of the floors and the roof and the live load, 
plus the weight of the tier of columns, which would be so small in 
proportion to the other loads that it need not be considered. If the 
columns were 14 feet apart longitudinally, each column would sup- 
port 224 square feet of each floor, so that the total dead load on the 
footing under the columns will amount to 114,240 pounds, and the pos- 
sible live load to 168,000 pounds. As it would be scarcely possible 
for every foot of floor on every floor being loaded to its full capacity 
at the same time, we would probably come nearer the actual condi- 
tions if we take only 50 per cent. of the total live load, or 84,000 
pounds, making a total load on the footing of 198,240 pounds, which 





* For weight per cubic feet of materials, see table in appendix. 


FOUNDATIONS ON FIRM SOILS. 25 


would require 33 square feet in the area of the footing. But as there 
will be no shrinkage or compression in the iron columns we had bet- 
ter reduce this area 10 per cent., making 30 square feet, or 5% feet 
square. 
The above calculations should be entered in a memorandum book, 
kept for the purpose, somewhat as follows: 
DATA FOR FOOTINGS. 


UNDER ONE FT. OF SIDE WALLS. UNDER COLUMNS. 
Cubic feet of brickwork, 108 @ 120=12,960 lbs. 
Cubic feet of stonework, 28@150= 4,200 





Total weight of wall... ... <. Tip, 100) LDSitce te cte ain cn eig Oo eea sees + OtHING 

PP OOHaL ea SUPOLlEd. STI" cw cicine ie tues vine Sais ep See ates hrs SOC 16 x 14=2240' 
Weight of floors per 0’ 75 lbs. 
Weight of roof per 0’ 60 lbs. 
PPOtatorsix NO0rs ahd: Fool? 510% Sa 4,080.6 2. 5. 50 tre wis ons 510 X 224=114,240 
Live load per 0'— 

Ist, 2d and 3d floors, 150 lbs. 

3d, 4th and 5th floors, 100 lbs. 

















Total live load, 8x ios OVO ce vie anew wes fe x Jae 168,000 
50%. Of this’ <=....6 sence eeeee 3y000, cee cee eee creer acre nee . 84,000 
Totalload Sc ecats aes apatc a 3 DEL DAO Mth Mirren chix Park eae Bd» ahora sa 198,240 


Assumed bearing load, 6,000 lbs. 
Width of footings under wall, 4 ft.; under columns, 330’ less 10%, or 5'6”x 5’ 6”. 


The front and rear walls, if continuous, would not have to support 
any floor loads, and the footings should be reduced in proportion. 
The footings under the piers supporting the ends of the girders should 
also be separately computed. 

28. In the case of light buildings it will often be found that the 
computed width of footings will be less than that required by the 
building ordinance, in which case it will of course be necessary to 
comply with the ordinances or building laws. As a rule, the footings 
under a foundation wall should be at least 12 inches wider than the 
thickness of the wall to give it stability. Even in light buildings the 
footings under the different portions of the buildings should be care- 
fully proportioned, so that all will bring the same pressure per square 
foot on the ground. In cases where the width of the footing is reg- 
ulated by the building law, the pressure per square foot under the 
footing should be computed, and the footings under all piers, etc., 
proportioned to this standard. In cases where a high tower adjoins 
a lower wall the footings under the two portions must be carefully 
proportioneé to the weight on each, otherwise the wall may crack 
where it is bonded into the tower. 

Example I7.—To illustrate the manner in which the width of the 
footings should be proportioned when the pressure under the footings 


26 BUILDING CONSTARCCLION: 


is very light, we will take the case of a one-story stone church, hav- 
ing side walls 20 inches thick and 22 feet high above the footings, 
and a tower at the corner 60 feet high, the first 22 feet being 24 
inches thick and the balance 20 inches thick. The roof is supposed 
to be supported by trusses and purlins, so that only the lower 6 feet 
of the roof rests on the side walls. The side walls also carry 6 feet 
of the floor; the tower has a flat roof 12 feet square. 

The computations for the weights on the soil under the side walls 
and under the tower wall would be as follows: 











UNDER SIDE WALLS. UNDER TOWER WALL, 
Stonework, 22’ x 20"= 36% Stonework, 22°x24°=".. ' 44°cu. ft, 
cu.ft. at 150 lbs. percu.ft., 5,500 lbs. pike ery re My hem eee ase 

Weight of first floor, 
130 lbs.x60'’= 780 ” 1074 XK 15O= emis Poe 16,100 lbs. 
Weight of roof below purlin, Weight of floor, 130x 6=.. 780 ‘! 
40 tbs xX Oe ==" 2400." Weight of roof, 4ox6=.. ZA s* 
Total weight on soil...... 6,520 ” 


Total weight on soil..... 17,120 ‘* 


Width of footings, 3 ft. 
Pressure per ©’ under footings, 2,173 lbs. 
Width of footings under tower, 17,120+2,173=7.8 ft. 


In this case the width of the footings under the side wall should 
be determined by the question of stability, and should not be less 
than 3 feet. Then if the pressure under the tower were reduced to 
the same unit per square foot, the tower footings would need to be 
nearly 8 feet wide. On firm soils, however, such as sand, gravel, or 
compact clay, it would not be necessary to make the footings so wide 
as this, as the soil would probably not settle appreciably under a con- 
siderably greater pressure, so that if the footings of the tower were 
made 6 feet wide, there would probably be no danger of unequal set- 
tlement. Of course the greater the unit pressure on the soil the more 
exact must be the proportioning of the footings. 

29. Centre of Pressure to Coincide with Centre of 
Base.—That the walls and piers of a building may settle uniformly 
without producing cracks in the superstructure, it is not only essen- 
tial that the area of the footings shall be in proportion to the load 
and the bearing power of the soil, but also that the centre of pressure 
(a vertical line through the centre of gravity of the weight) shal/ pass 
through the centre of the area of the foundation. 

This condition is of the first importance, for if the centre of pres- 
sure does not coincide with the centre of the base, the ground will 
yield most on the side which is pressed most, and as the ground 
yields the base assumes an inclined position and carries the lower 


FOUNDATIONS ON FIRM SOILS. 27 


part of the structure with it, thus producing unsightly cracks, if 
nothing more. | 

A case in which a violation of this rule cannot well be avoided is 
the foundation under the side wall of a building, where the tooting is 
not allowed to project beyond the lot line. In such a case the cen- 
tre of pressure is indicated by the downward arrow, and the centre of 
base by the upward arrow, Fig. 4. It is evident that the intensity of 
the pressure is greatest on the portion of the footing to the right of 
the centre of base, and the footing will in consequence settle ob- 
liquely as shown in the figure, having a tendency to throw the wall 
outward. ‘This tendency may be counteracted by tying the wall se- 
curely to the floor joist, but it would be much better if some arrange- 
ment could be made so that the footing would settle evenly. Where 


fl 





Fig. 4. Fig. 5. 


it is absolutely necessary to build the footing without projecting be- 
yond the lot line, the footing should be carefully built of dimension 
stone, or of hard brick, well grouted in cement mortar, and the foot- 
ing should be no wider than is absolutely demanded by the nature of 
the soil, and the offsets on the inside of the wall should be very 
slight. The footing shown in Fig. 4 is to be preferred to that shown 
in Fig. 5. . 

30. Fig. 6 illustrates another case where the centre of pressure 
comes outside the centre of base, consequently the wall inclines out- 
ward, producing cracks over the opening. This is a very common 
occurrence in brick and stone walls where wide openings occur. In 
such cases the footing under the opening should either be omitted 
entirely or made much narrower than under the pier, and the two 
should not be bonded together. Where several openings occur one 


28 BUILDING CONSTRUCTION. 


above the other, as in Fig. 7, and the footing is continued under the 
opening, the unequal settlement of the footings will very likely pro- 
duce cracks over all the openings, the side walls inclining slightly out- 
ward. Where the width of the opening is 8 feet or more, and the bot- 
tom of the opening is not a great ways 
above the footing, the footing under 
the wall on each side should be treated 
as under a pier, as shown in Fig. 8, 
and the space between the footings 
filled in with a dwarf wall only. If 
the bottom of the opening is twice its 
width above the foundation, the wall 
under the opening will distribute the 
weight equally over the footing and 
the settlement will be uniform. 

As a rule the foundation of a 
wall should never be bonded into 
that of another wal] either much 
heavier or much lighter than itself. 

The footings should also be proportioned so that the centre of 
pressure will strike a little zzsede of the centre of the base, to make 





Fig. 6. 





Fig. 7. Fig. &. 


sure that it will not be owfstde. Any inward-inclination of the wall 
is rendered impossible by the interior walls and the floors, while an 
outward inclination can be conteracted only by anchors and the bond 
of the masonry. Aslight deviation of the centre of the pressure out- 
side of the centre of the base has a marked effect, and is not easily 
counteracted by anchors. 


/ 


FOUNDATIONS ON FIRM SOILS. 29 


At Chicago an omission of 1 to 2 per cent. of the weight (by 
leaving openings) usually causes sufficient inequality in the settle. 
ment to produce unsightly cracks.* 

Where slight differences in weight occur, cracks may generally be 
prevented by building in hoop iron ties, rods or beams over the open- 
ings. It is also a wise precaution, where one wall joins another, either 
in the middle or at the corner of a building, to tie the walls together 
by long iron anchors built into the walls about every six feet in 
height. 

SUPERINTENDENCE. 


31. In inspecting the excavation the superintendent should first 
examine the lines to see that the building has been correctly staked 
out, and that the excavation is being carried at least 6 inches outside 
of the wall lines, so as to give room for pointing or cementing. If 
the wall is built against the bank it will be impossible to point up the 
joints on the outside, and the back of the wall not being exposed, 
the masons. are apt to slight that part of the work to the future detri- 
ment of the building; and if the excavation is not made large 
enough at first, it causes much trouble and vexation, as the work can- 
‘not be done as cheaply afterward, and the stone masons will very 
likely complain about being delayed. 

The superintendent should also see that the finished grade is 
plainly marked on some fixed object and caution the workmen not to 
dig the trenches below the level marked on the drawings. If the 
trenches are excavated below the proper level, they must not be 
refilled with earth, as the footings should start on the solid bottom of 
the trench; as this will require more masonry than the contractor 
estimated on, he will be quite sure to call for an extra payment for 
the same from the owner, unless the excavating is included in his 
contract, in which case he will have to settle with the excavator. 
For this reason it is a good plan to have the excavating included in 
the contract for the foundation. 

The superintendent should also examine the character of the soil 
at the bottom of the excavation, and if it is not such as was expected, 
the foundations must be changed or carried deeper, as previously 
described. Should water be encountered in making the excavation 
some provision should be made for draining the cellar, either by lay- 
ing a tile drain around the footings, or by laying the bottom courses 
dry and connecting with a stone drain, as described in Sections 6 and ro. 


* Prof. Ira O. Baker, C. E., in ‘* Masonry Construction.”’ 


30 BOLEDING- CON SIMCC TION, 


The specifications should provide that the contractor is to keep 
the trenches free from water while the wall is being laid. In places 
where the water cannot be drained off, it must be removed by a 
pump, either worked by hand or by steam. When the excavation is 
made close to an adjoining building the superintendent should see 
that the contractor has made proper provision for shoring or others 
wise protecting the adjacent walls. 


SRS, 


Cuapter II 


FOUNDATIONS ON COMPRESSIBLE SOILS. 


———_—__—. 


32. The soils of this class that are met with in preparing the foun- 
dations of buildings are generally along the shore of some large body 
of water, and hence generally permeated with water to within a few 
feet of the surface. 

For such soils pile foundations are usually the cheapest and most 
reliable. On a soil such as underlies Chicago, and having a support- 
ing power of from 1% to 2% tons per square foot, spread founda- 
tions may be used with satisfactory results and with economy, when 
it would require piles over 4o feet long to reach hard pan. 

Occasionally it is necessary to build on ground that has been filled 
in to a considerable depth, and in which water is not present, or the 
building may be so heavy that it is impracticable to support it on 
piles: in such cases wells of solid masonry, with an iron casing, or 
pneumatic caissons, should be sunk to bed rock or hard pan, as 
hereinafter described. 


PILE FOUNDATIONS. 


When it is required to build on a compressible soil that is con- 
stantly saturated with water and of considerable depth, the cheapest 
and generally the best foundation bed is obtained by driving piles. 

33. Classes of Piles.—A great many kinds of piles are used in 
engineering works, but for the foundations of buildings it is very sel- 
dom, if ever, that any other than wooden piles are used. 

The different conditions under which piles are used for supporting 
buildings may be classed as follows: 

rt. When the compressible soil is not more than 40 feet deep and 
overlays a bed of rock, gravel, sand, or clay, long piles should be 
driven to the rock, or one or two feet into the clay or sand, in which 
case tney may be considered as columns. 

2. If the soft soil is more than 4o feet deep piles varying from 15 to 
40 feet in length should be driven, according to the character of the 
soil, the sustaining power of the piles depending upon the friction 
between the pile and the surrounding soil. 


32 BUILDING CONSTRUCTION. 


3- Short piles, 10 to 15 feet long, are sometimes driven, particu- 
larly in Southern cities, to consolidate the soil and give it greater 
resisting power. As piles are seldom used in this way, this method 
of forming a foundation bed will be dismissed with the following 
quotation: 

34.— 

“*In some sections of the country, especially in the Southern cities, the soil is of 
a soft alluvial material, and in its natural state is not capable of bearing heavy 
loads. In such cases trenches are dug as in firm material, and a single or double 
row of short piles are driven close together, and under towers or other unusually 
heavy portions of the structure the area thus covered is filled withthese piles. The 
effect of this is to compress and compact the soil between the piles, and to a cer- 
tain extent around and on the outside, thereby increasing its bearing power; what- 
ever resistance the piles m+y offer to further settlement may be added, though not 
relied upon. These piles are then cut off close to the bottom of the trench, and 
generally 2 plank flooring is laid resting on the soil and piles, or a layer of sand or 
concrete is spread over the bottom of the trench to the depth of 6 inches or 1 foot; 
and the structure, whether of brick or stone, commenced on this. There is little 
cr no danger of such structures settling, and if they do the chances are that they 
will settle uniformly if the number of piles are properly proportioned to the weight 
directly above them; but if the piles are not so proportioned, the same number be- 
ing driven under a low wall as under a high wall, unequal settlement is liable to 
take place, causing ugly or dangerous cracks in the structure.”’* 

4. Sheet piles, consisting of two or three-inch plank driven close 
together, edge to edge, are often used to sustain a bank during exca- 
vation, but are seldom depended upon for permanent effect. 

35. Material.—Piles are made from the trunks of trees, and 
should be as straight as possible, and not less than 5 inches in diame- 
ter for light buildings or 8 inches for heavy buildings. The woods 
generally used for piles in the Northern States are the spruce, hem- 
lock, white pine, Norway pine, Georgia pine, and occasionally oak. 
In the Southern States Georgia or pitch pine, cypress and oak are 
used. Oak is considered as the most durable wood for piles, and is 
also the toughest, but it is too expensive for general use in the North- 
ern States, besides being difficult to obtain in long, straight pieces. 
Next to oak come Georgia pine, Oregon pine, cypress and spruce, in 
the order named. 

Of the 1,700 piles supporting the new Illinois Central Railway Station in Chi- 
cago, 32 per cent. were black gum, 22 per cent. pine, 7 per cent. basswood, 21 per 
cent. oak, 15 per cent. hickory, with a few maple and elm.. A less proportion of 
the hickory piles were broken or crushed than of any other wood. 

36. Pointing and Ringing.—Piles should be prepared for driv- 
ing by cutting off all limbs close to the trunk and removing the bark. 





*“ A Practical Treatise om Foundations.”” W. M. Patton. C. RE. 


FOUNDATIONS ON COMPRESSIBLE SOILS. 33 


The small end should be sharpened to a point 2 inches square, the 
bevel being from 18 to 24 inches long. The large end should be cut 
square to receive the blows from the hammer. 

Experience has shown that in soft and silty soils the piles can be 
driven in better line without pointing. A pointed pile, on striking a 
root. or similar obstruction, will inevitably glance off, and no avail- 
able power can prevent it; while a blunt pile will cut or break the 
obstruction without being diverted from its position. 


Piles that are to be driven in, or exposed to, salt water should be 
. thoroughly impregnated with creosote, dead oil of coal tar, or some 
mineral poison to protect them from the “teredo” or ship worm, 
which will completely honey- 
comb an ordinary pile in 
three or four years. 

Ringing.—When the pene- 
tration at each blow is less 
than 6 inches, the top of the 
pile should be _ protected 
from “brooming”’ by put- 
ting on an iron ring about 1 
inch less in diameter than 
the head of the pile, and 
from 2% to 3 inches wide by 
5 inches thick. It is better 
to chamfer the head so the 
ring will just fit on than to 
drive the ring into the wood 
by the hammer, as the latter 

Fig. 9. method is liable to split long 
pieces from the pile. 

When driving into compact soil, such as sand, gravel or stiff clay. 
the point of the pile is often shod with iron, either in the form of 
straps bolted to the end of the pile, as at a, Fig. 9, or by a conical 
cast steel shoe about 5 inches in diameter and having a 14-inch 
dowel 12 inches long fitting into a hole in the end of the pile and a 
ring put around the pile, as shown at 4, to prevent it from splitting. 
The latter method should be used in very hard soils. If straps are 
used, as at a, they should be 2% inches wide, % inch thick and 4 
feet long. 

37. Manner of Driving.—The usual method of driving piles is 
by a succession of blows given with a block of cast iron called the 





34 BUILDING CONSTROCTION. 


hammer, which works up and down between the uprights ot a frame 
or machine called a pile-driver. The machine is placed over the 
pile, so that the hammer descends fairly on its head, the piles always 
being driven with the small end down. The hammer is generally 
raised by steam power, and is dropped either automatically or by 
hand. The usual weight of the hammers used for driving piles for 
building foundations is from 1,200 to 1,500 pounds, and the fall 
varies from 5 to 20 feet, the last blows being given with a short fall. 

In driving piles care should be taken to keep them plumb, and 
when the penetration becomes small the fall should be reduced to 
about 5 feet, the blows being given in rapid succession. 

Whenever a pile refuses to-sink under several blows, before reach- 
ing the average depth, it should be cut off and another pile driven 
beside it. 

When several piles have been driven to a depth of 20 feet or more 
and refuse to sink more than % inch under five blows of a 1,200 
povnd hammer falling 15 feet, it is useless to try them further, as the 
additional blows only result in brooming and crushing the head and 
point of the pile, and splitting and crushing the intermediate portions 
to an unknown extent. 

‘Sometimes piles drive easily and regularly to a certain depth, and 
then refuse to penetrate farther; this may be caused by a thin stra- 
tum of some hard material, such as cemented gravel and sand or a 
compact marl. It may require many hard and heavy blows to drive 
through this, thereby injuring the piles, and perhaps getting into a 
quicksand or other soft material, when the pile will drive easily again. 
If the depth of the overlying soil penetrated is sufficient to give lat- 
eral stability, or if this can te secured by artificial means, such as 
throwing in broken stone or gravel,it would seem unwise to endeavor 
to penetrate the hard stratum, and the driving should be stopped 
after a practical refusal to go with two or three blows. The thick- 
ness of this stratum and nature of the underlying material should be 
either determined by boring or by driving a test pile, to destruction 
if necessary. In the latter case the driving of the remaining piles 
should cease as soon as the hard stratum is reached.” * 

If the hard stratum, however, is only 2 or 3 feet thick, with 
hard pan not more than 4o or 50 feet from the surface, the piles 
should be driven to hard pan for heavy buildings; but if the soft 
material continues for an indefinite depth below the hard stratum, 
the piles should be stopped when the stratum is reached. In such 





** A Practical Treatise on Foundations.’ W. M. Patton, C. E. 


FOUNDATIONS ON COMPRESSIBLE SOILS. 35 


cases, however, the actual bearing power of the piles should Le tested 
by loading one or more of the piles, as described in Section 4o. 


38. Bearing Power of Piles.—When driven in sand or gravel, 
or to hard pan, piles will carry to the full extent of the crushing 
strength of the timber, providing the depth of the pile is sufficient to 
secure lateral stiffness. 


“There are examples of piles driven in stiff clay to the depth of 20 
feet that carry from 70 to 80 tons per pile: there are many instances 
in which piles carry from 20 to 40 tons under the above conditions. 
After a pile has been driven to 20 feet in sand or gravel, any further 
hammering on the piles is a waste of time and money, and injurious 
to the pile itself.” * 


Piles driven from 30 to 4o feet in even the softest alluvial soils 
should carry by frictional resistance alone from ro to 12% tons. 


For the safe working loads on piles driven in different soils, the 
following table, compiled from the Augineering News formula, may 
be used with safety. The values are for minimum lengths of spruce 
piles and average penetration for last five blows of a 1,200 pound 
hammer falling 15 feet. When heavier loads than these must be 
carried, or the penetration is much greater, the actual bearing power 
of the piles should be determined by testing, unless it is already 
known from actual experience. 


ABLE II.—BEARING VALUE OF PILES. 


























ri PILE | AVERAGE| PENETRA-| LOAD IN 
peck LENGTHS. |DIAMETER| TION. TONS, 
Ee Ins. Ins. 

HP Sees cies 5 Ania ca Bom rate caneeD 40 10 6 24 
MIST E esi OS Ros a nary a rae 30 8 2 =) 
Soft earth with boulders or logs.... 30 8 14 ¥ 
Moderately firm earth or clay with 

POUR CT OT, LOPS Is oars cies ave si aie, «one 30 8 I | 9 
SHO CRE TLINOE CLOG estes, a'sce as clea) a2 6c 30 10 is 9 
WaTERSATIl cin to Ae orc aioe a eso sds che 30 8 | + 12 
FOURUD CADET Soper eter one 2k ohn tasesttoe ake wal 30 8 $ 12 
Firm earth into sand or gravel....... 20 8 } 14 
FEI CATT LOG Wore reeks an eee maine 20 8 O 20 
ACL piers te ox Real thee aie ely a meter wees ee 20 8 O 20 
Grave linn woe see ce es penn a eR Tare oat 15 | 8 oO 20 





When the penetration is less than that given above, for soft soils 
the safe loads may be increased according to the Lnginee -ing News 
formula given in the next paragraph. 


*‘* A Practical Treatise on Foundations.”’ 


36 BOLE DIN GICON ST EO CLION, 


There have been several formule proposed for determining the safe 
working loads on piles. Of these, the latest, known as the Angzneer- 
ing News formula, is generally considered to be the most reliable. 
It is claimed for this formula that it sets “a definite limit, high 
enough for all ordinary economic requirements, up to which there is 
no record of pile failures, excepting one or two dubious cases where a 
hidden stratum of bad material lay beneath the pile, and above which 
there are instances of both excess and failure, with an increasing pro- . 
portion of failures as the limit is exceeded.” 

The formula is: | 


Gafe load calheme eee 
S+I 





in which w=weight of hammer in pounds; 4, its fall in feet; 
s, average set under last blows in inches. 

39. Municipal Regulations.—The New York Building Law 
(1892) provides that 
‘* Piles intended for a wall, pier or post tu rest upon shall not be less than 5 inches 
in diameter at the smallest end, and shall be spaced not more than 30 inches on 
centres, or nearer, if required by the Superintendent of Buildings, and they shall 
be driven to a solid bearing. 

‘“No pile shall be weighted with a load exceeding 40,000 pounds. 

‘““The tops of all piles shall be cut off below the lowest water line. When 
required, concrete shall be rammed down in the interspaces between the heads of 
the piles to a depth and thickness of not less than 12 inches and for 1 foot in width 
outside of the piles.” 


The Boston Building Law requires that 


‘‘Where the nature of the ground requires it all buildings shall be supported on 
foundation piles not more than 3 feet apart on centres in the direction of the wall. 

Buildings over 70 feet in height shall rest, where the nature of the 
ground permits, upon at least three rows of piles, or an equivalent number of piles 
arranged in less than three rows. All piles shall be capped with block granite lev- 
elers, each leveler having a firm bearing on the pile or piles it covers.” 


In Chicago it is required that 
‘‘ The piles shall be made long enough to reach hard clay or rock, and they shall 
be driven down to feach the same, and such piles shall not be loaded more than 25 
tons to each pile.” 

General William Sooy Smith, in an address delivered March 31, 
1892, before the students of engineering of the University of Illinois, 
stated that “A pile at the bottom of a pit 30 feet deep and well into 
hard pan, or to the rock where this is within reach, can be safely 
relied upon to sustain from 30 to 40 gross tons.” 

4o. Experiments on the Bearing Power of Piles.—The 
following description of several tests made to deteymine the actual 


FOUNDATIONS ON COMPRESSIBLE SOILS. 37 


sustaining power of piles in various localities gives a good idea of the 
manner of making such tests, as well as the loads which it required 
to sink them: 


Chicago Public Library.—To determine the actual resistance of the piles 
on which it was proposed to erect the Public Library building in Chicago, the 
following test was made: In order to make the experiment under the same con- 
ditions as would exist under the structure three rows of piles were driven into the 
trench, the piles in the middle row being then cut off below the level at which 
those in the outside row were cut off, so as to bring the bearing only on four piles, 
two in each outside row. This gave the benefit arising from the consolidation of 
the material by the other piles. The piles were of Norway pine, 54 feet long, and 
were driven about 52} feet—about 27 feet in soft, plastic clay, 23 feet in tough, 
compact clay, and 2 feetin hard pan. They had an average diameter of 13 inches 
and area at small end of 80 square inches, 

On top of the four outside piles, which were spaced 5 feet apart on centres, 
15-inch steel I-beams were placed, and upon these a platform, 7x7 feet, composed 
of 12x12-inch yellow pine timbers. On this platform pig iron was piled up at 
irregular intervals. When 4 feet high the load was 45,200 pounds, and was then 
continued, until at the end of about four days it was 21 feet high, giving a load of 
224,500 pounds. Levels were taken, but no settlement had occurred. By the end 
of about eleven days the pile of iron had reached the height of 38 feet, giving a 
load of 404,800 pounds upon the four piles, or about 50.7 tons per pile. Levels 
were then taken at intervals during a period of about two weeks, and, no settle- 
ment having been observed, a load of 30 tons was considered perfectly safe. 

Perth Amboy, 1873.—Pretty fair mud, 30 feet deep. Four piles, 12, 14, 
-I5 and 18 inches diameter at top, 6 to 8 inches at foot, were driven in a square to 
depths of from 33 to 35 feet. A platform was built upon the heads of the piles and 
loaded with 179,200 pounds, say 44,800 pounds per pile. After a few days the 
loads were removed. The 18 inch pile had not moved, the 12-inch pile had set- 
tled 3 inches, and the 14 and 15-inch piles had settled to a less extent.* 


Buffalo, N. Y.—In the construction of a foundation for an elevator at 
Buffalo, N. Y., a pile 15 inches in diameter at the large end, driven 18 feet, bore 25 
tons for twenty-seven hours without any ascertainable effect. The weight was then 
gradually increased until the total load on the pile was 37} tons. Up to this 
weight there had been no depression of the pile, but with 37} tons there was a 
gradual depression which aggregated § of an inch, beyond which there was no 
depression until the weight was increased to 50 tons. With 50 tons there was 
a further depression of % of an inch, making the total depression 13 inches. Then 
the load was increased to 75 tons, under which the total depression reached 3} 
inches. The experiment was not carried beyond this point. The soil, in order 
from the top, was as follows: 2 feet of blue clay, 3 feet of gravel, 5 feet of stiff red 
clay, 2 feet of quicksand, 3 feet of red clay, 2 feet of gravel and sand and 3 feet of 
very stiff blue clay. All the time during this experiment there were three pile- 
drivers at work on the foundation, thus keeping up a tremor in the ground. The 
water from Lake Erie had free access to the pile through the gravel. 


*‘“A Practical Treatise on Foundations.”’ 
+‘* Masonry Construction.’’ Baker. 


38 BUILDING CONSTRUCTION. 


‘* Subsequent use shows that 74,000 pounds is a safe load.””—Paztion. 

Philadelphia.—At Philadelphia in 1873 a pile was driven 15 feet into soft 
river mud, and five hours after 7.3 tons caused a sinking of a very small frac- 
tion of an inch; under g tons it sauk 3 of an inch, and under 15 tons it sank 5 feet. 

‘The South Street bridge approach, Philadelphia, fell by the sinking of the 
foundation piles under a load of 24 tons each. They were driven to an absolute 
stoppage by a 1-ton hammer falling 32 feet. Their length wis from 24 to 41 feet. 
The piles were driven through mud, then tough clay, and into hard gravel.’’* 

The failure in this case may have been caused by vibrations which allowed the 
water to work its way down the sides of the piles and thus decrease the friction ; 
or, what is more probable, the last blow was struck on a broomed head, which 
would greatly reduce the penetration and cause the bearing power to be overesti- 
mated. 


When the penetration is very slight or unobservable, and the head 
much broomed, the broomed portion should be cut off and the blows 
repeated if the full load of the formula is to be put on the piles. 

41. Actual Loads on Piles.—The following examples of the 
actual loads which are carried by each pile under the buildings 
named will serve as a guide to architects erecting buildings in those 
localities : 

Boston.— Under Trinity Church, 2 tons each. 

Chicago.—New Public Library building, 30 tons. 

Schiller Building, estimated load 55 tons per pile; building settled from 1} to 
2} inches. : 

Passenger Station, Northern Pacific Railroad, Harrison Street: piles 50 feet 
long carry 25 tons each without perceptible settlement. 

The enormous grain elevators in Chicago rest upon pile foundations. Mr. Adler 
states that the unequal and constantly shifting loads are a severer test upon the 
foundations than a static load of a twenty-story building. 

New Orleans.—Piies driven from 25 to 4o feet in a soft, alluvial soil carry 
safely from 15 to 25 tons, with a factor of safety of 6 to 8.—Patton. 

42. Spacing.—Piles should not be spaced less than 2 feet on cen- 
tres, nor more than 3 feet, unless iron or wooden grillage is used. 

When long piles are driven nearer than 2 feet from centres there is 
danger that they may force each other up from their solid bed on the 
bearing stratum. Driving the piles close together also breaks up the 
ground and diminishes the bearing power. 

When three rows of piles are used the most satisfactory spacing is 
2 feet 6 inches from centres across the trench and 3 feet from cen- 
tres longitudinally, provided this number of piles will carry the weight 
of the building. If they will not, then the piles must be spaced closer 
together longitudinally, or another row of piles driven, but in no case 
drive two piles less than 2 feet apart from centres. 


* Trans. Am. Soc. of C. E., Vol. VII., p. 264. 


FOUNDATIONS ON COMPRESSIBLE SOILS. — 39 


In all cases, wherever buildings are supported, the number of piles 
under the different portions of the building should be carefully pro- 
portioned to the weight which they have to carry, so that every pile 
will support very nearly the same load. This precaution is of espe- 
cial importance when part of the piles must be loaded to their full 
capacity. 

43. Cutting Off and Capping.—The tops of the piles should 
invariably be cut off below low water mark, otherwise they would 
soon commence to decay. 

The cutting off of the piles in building foundations is generally 
done by means of a large cross-cut saw worked by two men. The 
tops of the piles should be left true and 
level and on a line with each other. A 
variation of 4 an inch in the top of the 
piles may be allowed, but it should not 
exceed this limit. 

Three methods of capping piles are 
commonly employed: 1. By granite 
blocks. 2. By concréte. 3. By tim- 
ber grillage. 

44. Granite Capping.—In Boston 
it is obligatory to cap the piles with 
blocks of granite, which rest directly 
on the tops of the piles. . If the stone 
does not fit the surface of the pile, or 
a pile is a little low, it is wedged up 
with oak or stone wedges. In capping 
with stone a section of the foundation 
should be laid out on the drawings 
showing the arrangement of the cap- 
ping stones. 

A single stone may rest on one, two 
or three piles, but zo¢ on four, as it is practically impossible to make the 
stone bear evenly on four piles. Fig. 10 shows the best arrangement 
of the capping for three rows of piles. Under dwellings and light 
buildings the piles are often spaced as in Fig. 11, in which case each 
stone should rest on three piles. After the piles are capped large 
footing stones, extending in one piece across the wall, should be laid 
in cement mortar, as shown in Fig. 12. 


45. Concrete Capping.—In New York a very common method 
of capping the piles is to excavate to a depth of 1 foot below the top 





Fig. ro. 


40 BUILDING CONSTEUCTION,. 


ot the piles and 1 foot outside of them, and fill the space thus exca- 
vated solid with rich Portland cement concrete, deposited in layers 
and weil rammed. After the concrete is brought level with the top 
of the piles additional layers are laid over the whole foundation until 
it reaches a depth of 18 inches above the piles. On this foundation 
bed, the brick or stone footings are laid as on solid earth. Many 
engineers consider this the best method of capping. There is cer- 
tainly no question of its durability, and it is believed that the con- 
crete will preserve the heads of the piles from rotting, provided the 
water is at all times up to the bottom of the concrete. A concrete 
beam 18 inches thick would also serve to distribute the pressure over 





Fig. rr. 


the piles better than the stone capping, although not to such an 
extent as heavy grillage.* If the soil is at all firm under the con- 
crete, it will also assist the piles in carrying the load when concrete 
capping is used. Under very heavy buildings the space between the 
piles to the depth of 1 foot should be filled with concrete, whatever 
kind of capping is employed. 

46. Grillage.—In Chicago most of the “pues having pile foun- 
dations have heavy timber grillage bolted to the tops of the piles, and 
on these timbers are laid the stone or concrete footings. For build- 
ing foundations the grillage usually consists of 12x12 timbers of the 
strongest woods available, laid longitudinally on top of the piles, and 





* By inserting twisted iron bars in the top and bottom +f she concrete ‘¢ may also be gives, 
great transverse strength. 


LOUNDALTTIONS ON COMPKESSIBLE SOILS. 41 


strongest woods available, laid longitudinally on top of the piles, and 
’ fastened to them by means of drzf¢t do/ts, which are plain bars of iron, 
either round or square, driven into a hole about 20 per cent. smaller 
than the iron. One-inch round or square bars are generally used, the 
hole being bored by a #-inch auger for the round bolts or a {-inch auger 
for the square bolts. The bolts should enter the pile at least 1 foot. 

If heavy stone or concrete footings are used, and the space between 
the piles and timbers is filled with concrete level with the top of the 
timbers, no more timbering is required; but if the footings are to 
be made of small stones, and no concrete is used, a solid floor of cross 
timbers, at least 6 inches thick, for heavy buildings should be laid on 
top of the longitudinal capping and drift-bolted to them. 

Where timber grillage is used it should, of course, be kept entirely 
below the lowest recorded water line, otherwise it will rot and allow 
the building to settle. It has been proved conclusively, however, that 
any kind of sound timber will last practically forever if completely 
immersed in water. 

The advantages of timber grillage are that the timbers are easily laid 
and effectually hold the tops of the piles in place. They also tend to 
distribute the pressure evenly over the piles, as the transverse strength 
of the timber will help to carry the load over a single pile, which for 
some reason may not have the same bearing capacity as the others. 

Steel beams, imbedded in concrete, are sometimes used to distrib- 
ute the weight over piles, but some other form of construction can 
generally be employed at less expense and with equally good results. 

Objections to Pile Foundations.—It has been claimed that 
driving piles in a soil such as that under Chicago, within a few feet 
of buildings having spread foundations, has a tendency to cause the 
latter to settle so as to necessitate underpinning. 

On driving the first piles for the Schiller Building it was found that 
an adjoining building had settled 6 inches, and it had to be raised on 
screws. 

The driving of piles also causes a‘readjustment of the particles of 
clay and sand into a jelly, thus destroying the resisting qualities. 
These objections, however, are not of so much moment when the 
adjoining buildings are supported by piles. 

SPREAD FOUNDATIONS. 

Compressible soils are often met with which will bear from 1 to 2 
tons per square foot with very little settlement, and, as a rule, this set- 
tlement is uniform under the same unit pressure (pressure per square 
foot). In such cases it is often cheaper to spread the foundations so 


42 BUILDING *CONSLAUGLION: 


as to reduce the unit pressure to the capacity of the soil than to 
attempt to drive piles. “Spread” footings may be built of concrete 
with iron tension bars, of steel beams and concrete, or of timber and 
concrete. 

48. Concrete with Iron Tension Bars.—When the neces- 
sary height can be obtained, spread footings composed of Portland 
cement concrete, with iron tension members, have more qualities to 
recommend them than any other construction. Such footings are 
easy of construction, they are cheap, and their durability is everlast- 
ing. The iron being so completely imbedded in the concrete it can- 
not rust,* and hence there is no possibility of deterioration in the 
footings. 

Masonry is undoubtedly the natural material for foundations, and 
the author believes that it should be preferred to iron or steel wher- 
ever practicable. 

By the use of twisted iron rods the concrete footings may be made 
of equal transverse strength as footings of steel beams, but they 
require more height. 





Fig. 13. 


Fig. 13 shows the most economical section for a concrete and 
twisted iron footing. In building the footings with steel beams, the 
strength of the concrete is practically wasted, while in this method of 
construction it is all utilized. It has been proved that the entire ten- 
sile strength of the twisted bars can be utilized, and, being held con- 
tinuously along their entire length by the concrete as a screw bolt is 
held by the nut, they neither draw nor stretch, except as the concrete 
extends with them. : 

In building concrete footings, as shown in Fig. 13, a layer of con- 
crete from 3 to 6 inches thick, made in the proportion of 1 to 
3, Should first be laid, and’ the iron bars laid on and tamped down 


* In cutting through a portion of a foundation built of concrete and iron, and submerged in 
“alt water, ten years after the work was done, no deterioration to the iron whatever was found. 
Yron imbedded in concrete, with the end projecting, has been found bright and clean after the 
projecting end had completely rusted away. 


PEUNDVATIONS ON COMPRESSIBLE: SOILS. 43 


into it. Another layer of 4 inches, mixed in the same proportion, 
should then be laid, after which the concrete may be mixed in the pro- 
portion of one to six. Each layer should be laid before the preced- 
ing layer has had time to harden, otherwise they may not adhere 
thoroughly. 

The author has prepared Table III., giving the strength and pro- 
portions of footings constructed in this way, which he believes to have 
a large margin of safety. Two sizes of bars are given, with the cor- 
responding safe loads for the footings, the other measurements apply- 
ing to both cases. The measurements in the third column refer to 
the width of the brick or stone footing resting on the concrete. The 
greater the width of this footing in proportion to the width of the 
concrete, the less will be the strain on the tension rods. 


TABLE III.—PROPORTIONS AND STRENGTH OF CONCRETE FOOTINGS WITH 
TWISTED IRON TENSION BARS. 























al a oa . io) Sans ax Sie. 
CUE moe eet <) Of BY | mw Si fa a3 
woe} 268 mee | Seat | Of » Sze Oma. | Qa 
& & Se es <5u < ro) < HO 
Sas ie, De Ge an re a HS aos 4 
Be. | Sad | GhS | GEE. | 858 | BUS | kBa jece 
Sr Taek neds eae ing an Soi choy om < i a a < i 
nA, wa, 
Pee ins bh teetn: Inches. Inches. Tons. Inches. | Tons. 
20 oh 1S Onn 8 2 78 1% 66 
18 3. 3 SO eee 2 76 If 56 
16 2) 16 5 O 7 1? 73 I} 50 
14 vy Ye Ae 7 | 13 70 12 49 
12 2 6 4 4 6 12 65 I} 48 
10 2 a 4 oO 6 I; 65 I 42 
8 oh Ves) AF 0 6 I 60 ¢ 40 
6 I 8 Su, 30 6 55 2 29 








Piers.—Footings for piers may be built in the same manner, with 
two sets of bars laid crossways of each other, and also diagonally, as 
shown in Fig. 14. In the case of piers the corners should be cut off 
at an angle of 45 degrees, as shown. ‘The same size of bars should 
be used for a pier as for a wall, whose footings have the same pro- 
jection beyond the masonry, and the depth of the concrete should be 
the same. 

Lxample.—What would be the safe load for a pier footing 14 feet 
square, with a stone footing on top 6 feet square, the corners being 
cut off, as in Fig. 14? 

Answer.—The area of the pier footing would be 196—32=164 
square feet, and the projection of the footing beyond the masonry 
would be 4 feet. In Table III. we find that the projection of the 
12-foot footings is 3 feet 10 inches, and that the safe load for this 


44 BUILDING CONSTRUCTION. 


footing (with 14-inch bars) is 48 tons, or 4 tons per square foot. If 
we make our pier .f the same thickness and use 14-inch bars we 
-would have the same strength per square foot, which would give a 
total safe load on the footing of 656 tons. 

Unfortunately this method of construction, including all forms of 
concrete construction with twisted tension rods, has been patented by 
Ernest L. Ransome, of San Francisco, Cal., and the rights are now 
owned by the Ransome & Smith Co., of New York, Chicago and San 
Francisco, to whom a royalty must be paid when twisted bars are 
used ; but even after paying the royalty it is much the cheapest foot- 
ing for the strength obtained. 


Pine eine 
te eke 
TORTS 





Fig. 14.—Plan of Pier. 


This form of construction has been used to a considerable extent 
in San Francisco. 
STEEL BEAM FOOTINGS. 


49. When it is necessary to spread the foundations over 12 or 15 
feet in each direction, with a very small height to the footings, as is 
the case in Chicago, steel beams must be used to furnish the neces- 
sary transverse strength. Even when building on solid ground, it is 
claimed that iron and steel footings for tall buildings, at the present 
price of steel (1895), are cheaper than masonry footings. The author 
doubts, however, if steel footings will prove as durable as those of 
masonry. | 


FOUNDATIONS ON COMPRESSIBLE SOILS. 45 


The manner of using the beams is shown in Figures r5 to 18. 

In preparing the footings, the ground is first carefully leveled and 
the bottom of the pier located. If the ground is not compact enough 
to permit of excavating for the concrete bed without the sides of the 
pit or trench falling in, heavy planks or timbers should be set up and 
fastened together at the corners, and, if necessary, tied between with 
rods, to hold the concrete in place and prevent its spreading berore 
it has thoroughly set. A layer of Portland cement concrete, made in 
the proportion of 1 to 6, and from 6 to 12 inches thick, accord- 
ing to the weight on the footings, should then be filled in between the 
timbers and well rammed and leveled off. If the concrete is to be 12 
inches thick it should be put in in two layers. Upon this concrete 
the beams should be carefully bedded in 1 to 2 Portland cement 
mortar, so as to bring them nearly level and in line with each other. 


The distance apart of the beams, from centre to centre, may vary 
from g to 20 inches, according to the height of the beams, thickness 
of concrete, and estimated pressure per square foot. They must not 
be so far apart that the beams will crush through the concrete (see 
Section 53), and on the other hand there must be a space of at least 
2 inches between edges of flanges to permit the introduction of the 
concrete filling. As soon as the beams are in place the spaces 
between them should be filled with 1 to 6 concrete, the stone 
being broken to pass through a 1$-inch ring, and the concrete well 
rammed into place, so that no cavities will be left in the centre. The 
concrete must also be carried at least 3 inches beyond the beams on 
sides and ends, and kept in place by planks or timbers. 

50. If two or more layers of beams are used, the top of each layer 
should be carefully leveled (after the concrete has been put in place) 
with xr to 2 Portland cement mortar, not more than $ inch thick 
over the highest beams, and in this the next layer ot beams should 
be bedded, and so on. 

The stone or metal base plate or footing should also be bedded in 
Portland cement mortar, not more than ? inch thick, above the upper 
tier of beams. 

After the base plate or stone footing is in place at least 3 inches of 
concrete should be laid above the beams and at the sides and ends, 
and when this is set the whole outside of the footings should be plas- 
tered with 1 to 2 Portland cement mortar. 

Mr. George Hill, Consulting Engineer, recommends that before lay- 
ing the steel beams two thicknesses of tarred felt laid in hot asphalt 
should be spread over the concrete, and on top of this a Jayer of rich 


40 BUILDING CONSTRUCTION. 


cement mortar 14 inches thick, in which the beams should be placed. 
He also recommends that the whole ooting be covered with two 
coats of hot asphalt. 

51. Before the beams are laid they should be thoroughly cleaned 
with wire brushes, and, while absolutely dry, either painted with iron 
paint or else heated and coated with two coats of asphalt. Before 
covering the beams with the concrete every portion of the metal 
should be carefully examined, and wherever the paint or asphaltur 
has been scraped off in handling, the iron should be thoroughly dried 
and the coating renewed. 

Every pains should be taken to protect the beams from rusting, for, when unpro- 
tected, steel beams rust very quickly, and if once the beams were subjected to the 
rusting process it would probably not be long before’ the building commenced te 
settle. -« 

52. When iron and concrete foundations were first used in Chicago’ 
railway rails were employed, on account of their lesser cost, to give 
the transverse strength. 

The footings were built up with five or six layers of rails, placed at 
right angles to each other, each layer diminishing in number until 
the upper surface was stepped off small enough not to unduly exceed 
the proper size of the column base. As each layer of rails was laid, 
concrete was filled between and around them, and when completed 
the footing resembled a simple concrete pier. 

The footings under the Rand and McNally Building (erected in 1891) were ot 


this character, five layers of rails being used in most of the footings. In some of 
the footings the upper layer consisted of 12-inch beams, 


Building up the footings in successive tiers, however, is not as eco- 
nomical in the use of the steel as when two layers of deep beams are 
used. The beams being large and smooth, the concrete does not 
unite with them to form a composite beam, as is the case in the Ran- 
some construction ; therefore, no dependence at all can be placed on 
the concrete for spreading the weight. 

It should also be borne in mind that the beams spread the load 
over the ground only by their transverse strength, and they should, 
therefore, be used in the same way that they would be were the foun- 
dation reversed, the wall or column becoming the support and the 
ground the load. 

53. When several beams are used in the upper course or layer 
there is a tendency to concentrate the weight on the outer beams of 
the upper layer, owing to the deflection of the beams below. The 
author therefore advocates the use of as few beams as practicable ir 


FOUNDATIONS ON COMPRESSIBLE SOILS. 47 


the upper course, and where the conditions will permit either a single 
built up girder or two heavy beams, and in the lower course the 
deepest beams consistent with economy. If the beams in the lower 
course permit of a spacing much greater than their height, a layer of 
rails should be imbedded in the top of the concrete to prevent the 
beams from breaking through. The rails, however, would in no way 
affect the stress or bending action in the beams. 

For a further discussion of the use of steel beams in foundations, the reader is 
referred to an article by the author in Architecture and Building of Aug. 24, 1895. 


Examples of steel beam and concrete footings are also given, with illustrations, 
in the Exgineering Record of December 12, 1891, and June I, 1895. 


Method of Determining the Size of the Steel Beams. 

54. A. Under a Wall—aAs the duty of the beams is to distribute 
the load coming from the foundation wall or base plate evenly over 
the ground, so that the pressure on each square foot of the soil will 










YUMMY, 
Uf 


U4. Wn, 







NSNSS 








oa Se ARIMA eee eet PH cat tal ot 

- oe ioe = LY x as’ = 
Fal arene eS wa PAN acall Sine wiaiaiai st serait e ae isies ea eet aa 
Ein Tk SOOT i Tae he UM ke et es ea ak a a a tat WA 





CROSS SECTION. : SIDE VIEW, 
Fig. 15. 


be the same, it is obvious that the beams must have sufficient trans- 
verse strength to keep them from bending, so that they will settle as 
much at the outer ends as under the centre. The effect on the 
beams shown in Fig. 15, when resting on a compressible soil and 
heavily loaded from above, is to cause the ends of the beams to bend 
upward, thus straining the beams most at the centre; the stress in 
the beams. being the same as if they were supported at the centre and 
loaded with a distributed load. The maximum bending moment is 
also the same as for a beam fixed at one end and uniformly loaded, 
so that the beams are usually calculated by the formula for a beam 
fixed and loaded in that way. | 

The readiest method of determining the size of the beams is by 
computing the required coefficient of strength and finding in the tables 
of the manufacturers the size of beam which has a coefficient equal 
to or next above the value obtained by the formula. The coefficient 


48 BUILUING CONSTRUCTION. 


of strength, generally represented by the letter C, is given in the cat- 
alogues of the companies that roll beams, and may also be found in 
the tables of beams in the Architects’ and Builders’ Pocket Book. 


The formula for the coefficient of strength for beams under a wall, 
as in Fig. 15, and also for the lower tier of beams under a pier, is 


CARD XS arse joblae ee tae eke ds Were ts) aio kcintelneirara ve ers tess (1) 


in which w represents the assumed bearing power in pounds per 
square foot ; £, the projection of the beam in feet, and s, the spacing 
or distance between centres cf beams, also in feet. 


Owing to the tendency of the beams in bending, to concentrate the 
load on the outer edges of the masonry footing, and thus crush them, 
which action would have the same effect on the beam as lengthening 
the arm or projection (see article in Architecture and Building pre- 
viously referred to), the author recommends that when the course 
above the beams is of stone, brick or concrete, at least one-third the 
width of the masonry footing de added to the actual projection. The 
calculations above indicated will be more clearly shown by the fol- 
lowing example : 

Lxample J.—A building is to be erected on a soil of which the safe 
bearing power is but 2 tons, and the pre-sure on each lineal foot of 
wall is 20 tons. It is decided to build the footings as shown in 
Fig. 15. What should be the dimensions and weight of the beams? 


Answer.—As the total pressure under each lineal foot of wall is 20 
tons, and the safe bearing power of the soil 2 tons, the footings must 
be 20+2, or 10 feet wide. We will use 4-foot granite blocks for the 
bottom course of the wall, which will give an actual projection (P) 
of 3 feet for the beams. For making the calculations we will add to 
the actual projection one-third of 4 feet, or 16 inches, making the 
value of 4% feet. We will assume 1 foot for the spacing of the 
beams, so that s will equal 1. The beams must then have a coeffi- 
cient of strength = 4X wp Xs=4 X 4000 X (44) X 1=304,000 Ibs. 
Examining the table giving the properties of Carnegie steel beams, 
we find that a ro-inch 33-pound steel beam has a coefficient of 344,- 
ooo pounds, and a 25-pound beam 261,000 pounds; therefore, we 
must use 33-pound steel beams 1o feet long. If we spaced the 
beams ro inches on centres, s would equal 4 and C would equal 
4X 4000 X (44)? X%, or 253,500 pounds, which would enable us to 
use 25-pound beams, thereby effecting a saving of 30 pourds to the 
lineal foot of wall. 


FOUNDATIONS ON COMPRESSIBLE SOILS. 49 


55. To facilitate making the above calculations, the Carnegie Steel 
Company publishes the following table giving the safe projection of 
Carnegie steel beams, spaced 1 foot on centres, and for bearing values 
ranging from 1 to 5 tons: 


TABLE IV.—SAFE PROJECTIONS IN FEET OF STEEL BEAMS IN FOUNDATIONS, 



































xd aS 

te bee 

= - BEARING POWER IN TONS PER SQUARE FOOT. 

te ES 

- ~ 

aie : a 
be 3 Teepe Tee Lea ert ete 2h Shey Se | 4 | AR tS 
a) 2 

In Lbs a 

20 80. TA Out 2:5 Io. 0.0456.0 19.07) S20.) 7.57.0.) 6.8 1 6.0 

20 64 LACS ie OW FO. O51 16, Orta. 0.10720 oO. he) 6.06.0. hb B.S 
15 75. PLeSaerO. 5.10 O51, One ges on febu le O.5 6.0 | 6.0 5a 0 
T5700: TOV Or) ere Sele eS 2O 1 On 5.) OFO 19525 § 6.5 | B20 | 5.0 
15 50. suey te Or On Ons | O20) 5, 57(55.0 4 °5.0° (4.5 1.4.8 
15 At. Sesto ef One O-OUlOnOd 5.5 $6.04 4.5 0 4-5°(4.0 14.0 

12 4o. SLO 72Gier O25it mae54 5250 5.00 425° 4.04) 4,013.5) F6g 

12 22. FeO Ose sc5iees Ogea. Sola he A. Os 4,0 (635: eek bh 70 

1 ce) aoe Gshu O.CNms ey fr 4S dS old Ob 4.0 (3.5. 103.5: be 8.0 Fro 

10 Aa ec GO Gras Fr Oui A Onl 3.5 eae ho Let 12300 12.61 52.5 
9 owl eee Pant AG Oni. 3. Gob Shes OTR 6 O 1 Doe b8 8 
9 or. eae eral eg h es Oe ESO. |e 8. ) 208 ele) ol} 
8 22. EOnete ni eeasO Te Seas eet es. Ol. 2. ONC Bel 25162. 8) 12 Oo 
8 18. 4.5] 4.0] 3.5| 3.0] 3.0] 3.0 | 2.5 | 2.5 | 2.0 | 2.0 | 2.0 
#i 20, MoeMeaH OMe sais ONS Onlas,O t 2e58 12 2Rt2.0 1° 2/0°12,0 
7 Poca Oreo Salt S/O fos 182 Gale 2.5 12. O 1 2.0.) 2.0 12.0 | 2.8 
6 16. Byes. Ole 4 Oer2.5 205 162.0 162,0.1°2.0 1.305 | 1.5 } 2.5 
6491.23 Somes Ole ye cae 202 Om 2.0 1 ToS Vere bal To5 | 71.5 
5 13; SOE Geet Goes 2 Oriel O 2.0 Wel 501 155 ede Ale We 
5 10. Aree Dred) 2. Oo eo Orme er Slt a6) Ts 5 ait hil sce 
4 10. Gone Ome 2G) Bt St Oe eros 25 

4 Peseta Cue ee Oe 5 Pete S Pel, Say Ts Bat? oe 











_— 


Values given based on extreme fibre strain of 16,000 pounds per square inch. 


By the use of this table no calculations are necessary except to 
- determine the length and projection of the beams. If the beams are 
- to be spaced more or less than r foot from centres, the bearing power 
must be increased or decreased in the same ratio in using the table. 
The results obtained by this table should agree with the result 
obtained from formula r. 

Thus, in the above example, to use the table, we simply look down 
the column headed 2 until we find the projection nearest to (above) 


50 BOLLDINGAGOIV SS eC 12 Os 


4 feet, which in this case is 4.5, and opposite it we find a 10-inch, 
33-pound beam. 


To use the table for a spacing of ro inches we must take five-sixths 
of the bearing power, or 13 tons. ‘There is no column headed 13, but 
it would come between 1$ and 2. For 14 tons the projection of a 
1o-inch, 25-pound beam is 4.5, and for 2 tons, 4 feet. At the same 
ratio the projection for 1% tons would be about 4.3 feet. 


When there is no column corresponding with the bearing power it 
will be safer to use formula 1. 


56. B. Beams Under Piers (Fig. 16).—In this case the size of the 
lower beams are determined in the same way as in Kxample L., the 
length of » being taken from 
the end of the beam to the cen- 
tre of the outer beam in upper 
tier. 

For the upper beams the load. 
borne by each beam should be 
computed and the coefficient 
of strength determined by the 
, formula 





of the beam in pounds, and 
p the distance from end of 
beam to edge of iron plate 
above. 

Lxample LI.—The basement 
columns of a ten-story building 
are required to sustain a per- 
manent load of 400,000 pounds. 
What should be the size of the 
beams in the footings, the supporting power of the soil being but 2 
tons? 





SECTION. 
Fig. 16. 


Answer.—Dividing the load by the bearing power of the soil we 
have 100 square feet, or 10 X ro feet, for the area of the footing. We 
will arrange the beams as shown in Fig. 16, using a cast iron bearing 
plate 3 feet square under the column. The distance between the 
centres of outer beams in upper tier we will make 32 inches, thus 


FOUNDATIONS ON COMPRESSIBLE SOILS. 51 


fae " 
making the value of # for the lower beams = eS or 3% feet; 


s we will make 12 inches, or 1. 

Looking down column headed 2 (Table IV.) we find the nearest 
projection above 33 is 4, which is opposite the g-inch, 27-pound 
and also the 1o-inch, 25.5-pound beams. The latter being the 
lighter and also the stiffer, we will use for the lower tier. 


For the upper tier we see that the five beams must support an area 
equal to a, d, ¢, d, which in this case equals 34 X ro feet, or 35 square 
feet. As the pressure on each foot is 2 tons, we will have a total 
pressure of 70 tons on the ends of the five beams, or 14 tons or 
28,000 pounds oneach beam. ‘Then by formula 2 we find the coeffi- 
cient of strength must —4 X 28,000 X 3$=392,000 pounds. 

From the table of the Carnegie Steel Company’s beams we find 
that the coefficient for a 12-inch, 32-pound beam is 395,200 pounds; 
therefore, we will use three 12-inch, 32-pound beams and two 

; 40-pound beams in 


f the upper tier. 


| b é 57. as ae 
: NA SZ €am for the weight 
IRRReE, should always tk 
ae ES B 

WZ used, and unless the 
5. il beams in the upper 
tier have considerable 
excess of strength, 
the two outer beams 
should be heavy 
beams. 

When the footings 
carry iron or steel 
columns in the basement, as is generally the case, a cast iron or steel 
base plate should be used, as shown in Figs. 17 and 18. This plate 
should be bedded in Portland cement directly above the beams, as 
described in Section 50. 

Two and even four columns are often supported on one footing, as 
shown in Figs. 17 and 18. In such cases the computation becomes 
more elaborate, and an engineer should be called into consultation 
unless the architect is himself sufficiently familiar with such calcula- 
tions. 

Fig. 19 shows an arrangement in which a built-up base plate or 
girder is used in place of the upper tier of beams. The author 











~ 















Fig. 17. 


52 BUILDING CONSTRUCTION. 


believes this arrangement much better than that shown in Figs. 16 
to 18. 

In placing the beams, it is essential that they be arranged symmet- 
rically under the base plate, otherwise they will sink more at one side 
than at the other. When several unequally loaded columns rest on 
the same footing, the equal distribution of the weight on the soil 
becomes a difficult problem. 


TIMBER FOOTINGS. 


58. For buildings of moderate height timber may be used for giv- 
ing the necessary spread to the footings, provided water is always 
present. The footings should be built by covering the bottom of 
the trenches, which should be perfectly level, with 2-inch plank laid 





close together and longitudinally of the wall. Across these heavy 
timbers should be laid, spaced about 12 inches from centres, the size 
of the timbers being proportioned to the transverse strain. On top of 
these timbers again should be spiked a floor of 3 inch plank of the 
same width as the masonry footings which are laid upon it. A sec-_ 
tion of such a footing is shown in Fig. 20. 

All of the timber work must be kept below low water mark, and 
the space between the transverse timbers should be filled with sand, 
broken stone or concrete. The best woods for such foundations are 
oak, Georgia pine and Norway pine. Many of the old buildings in 
Chicago rest on timber footings. 


ves 


FOUNDATIONS ON COMPRESSIBLE SUILS. 











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Ae 09, Ristete o ¥,'d6 4" Pay 


Zinch Plank. 


Fig. 20, 


54 HOT LDING CONSTRUCTION. 


59. Calculation for the Size of the Cross Timbers.— 
The size of the transverse timbers should be computed by the fol 


lowing formula: 
2xXwxp*?Xs 


Breadth in inches ice pe ee (3) 
w representing the bearing power in pounds per square foot; /, the 
projection of the beam beyond the 3-inch plank in feet; s, the dis- 
tance between centres of beams in feet, and J, the assumed depth 
of the beam in inches. J is the constant for strength, and should 
be taken at go for Georgia pine, 65 for oak, 60 for Norway pine and 
55 for common white pine or spruce. 

Example J.—TVhe side walls of a given building impose on the 
foundation a pressure of 20,000 pounds per lineal foot ; the soil will 
only support, without excessive settlement, 2,000 pounds to the 
square foot. It is decided for economy to build the footings as 
shown in Fig. 20, using Georgia pine timber. What should be the 
size of the transverse timbers ? 

Answer.—Dividing the total pressure per lineal foot by 2,000 
pounds, we have ro feet for the width of the footings. The masonry 
footing we will make of granite or other hard stone, a feet wide, and 
solidly bedded on the plank in Portland cement mortar. The pro- 
jection ~ of the transverse beams would then be 3 feet. We will 
space the beams 12 inches from centres, so that s=1, and will assume 
to inches for the depth of the beams. Then by formula 3, breadth 
2X 2000 X9Q9XI 

100 X go 
inches from centres. If common pine timber were used we should 
substitute 55 for go, and the result would be 64. 

60. When building on quicksand it is often advantageous to lay a 
floor of 1-inch boards in two or more layers at right angles to each 
other on which to start the concrete footings. 


61. Foundations for Temporary Buildings.—When tem- 
porary buildings are to be built over a compressible soil, the founda. 
tions may, as a rule, be constructed more cheaply of timber than of 
any other material, and in such cases the durability of the timber 
need not be considered, as good sound lumber will last two or three 
years in almost any place if thorough ventilation-is provided. 

The World’s Fair buildings at Chicago (1893) were, as a rule, sup- 
ported on timber platforms, proportioned so that the maximum load 
on the soil would not exceed 1} tons per square foot. Only in a few 
places over “mud holes” were pile foundations used. 


in inches = =4, or we should use 4” X 10” timbers, 12 


FOUNDATIONS ON COMPRESSIBLE-SOILS. 55 


The platform foundations consisted of “3-inch pine or hemlock 
planks, with blocking (transverse beams) on top, to distribute the 
pressure from the loads uniformly over all the planks and to furnish 
support for the posts which carry the caps supporting the floor joists 
and posts of the building. The blocking was well spiked to platform 
planks and posts, and caps and sills drift bolted.” 


Fas 


CG AE Aas 
ERS 

| SUES | 
MANS fre= 
CH 








Fig. 21 shows the general arrangement of the blocking under the 


posts. 
MASONRY WELLS. 


62. When it is necessary to support very heavy buildings on com- 
pressible or filled soil, where piles or spread footings cannot be used, 
or are not considered desirable, wells of masonry, sunk to bed rock 
or hard pan, will generally prove the next cheapest method of secur- 
ing an efficient foundation. The wells are arranged as isolated piers, 
and the walls of the superstructure carried on steel girders resting on 
these piers. 

The manner in which such wells or piers should be used can prob- 
ably be best explained by describing those under the City Hall of 
Kansas City, Mo., which was one of the first instances in which such 
wells were used in this country.* 

* The following description is an abstract of a short paper presented by the architect of the 
building, Mr. S E. Chamberlain, of Kansas City, to the twenty-fourth annual convention of the 
American Institute of Architects The illustrations were prepared in the office of the Engineer. 


tng Record from the architect’s drawings. Several more illustrations are given in the Zngz 
neering Record of April z and 16, 1892. 


56 BUILDING CONSTRUCTION. 


‘‘ The site of the City Hall was formerly a ravine between abrupt bluffs. These 
had been so cut away and leveled as to leave a 50-foot filling of rubbish under two- 
thirds of the building and a solid clay bank under the other third. The fill was 
made by a public dump. Pile foundations were objectionable on account of the 
dryness of the fill and the anticipated tendency of the piles to rot therein. Ordi- 
nary trenching was considered too expensive and dangerous, therefore a system of 
piers was chosen, and a cylindrical form was adopted, so that the excavation could 
be done by a large steam power auger, followed by a ;,-inch caisson filled with 
vitrified brick. The caissons were made in 5-foot lengths of the same thickness 
throughout, the joints being made with 3"4" splice plates, riveted to the inside of 
the shell. 

‘‘The piers were of vitrified brick, 4 feet 6 inches in diameter, laid in hydraulic 
cement mortar, grouted solid in each course, and well bonded in all directions. 
The piers were sunk to bed rock of oolitic limestone, 8 feet thick, and capped with 
cast iron plates (Fig. 22) and steel I-beams, which supported the walls. To the 
top of the beams was riveted a }-inch plate of boiler iron, on which the brickwork 
of the walls was built, as shown in Fig. 23. 

‘* Between the beams, and 1 foot on each side and underneath them, is a con- 
crete filling, so that the beams are entirely encased in masonry. 

‘‘ Piers having excessive loads are reinforced by 12-inch Z-bar columns resting 
on rock bottom (Fig. 24). These columns pass through the cast iron caps. so that 
the loads resting on the columns are separate from those on the brick piers (an 
essential provision). Essentially the whole system is intended to secure the direct 
transmission of the entire weight to the solid rock by so arranging the interior con- 
struction that each subdivision is carried by an adequate isolated pier. The piers 
are cf uniform size, and their loads are equalized by spacing them at proportionate 
distances apart.” 


63. Another instance of the use of masonry wells or ucc 
in the foundation of the new Stock Exchange in Chicago. 


re ecrouls 


‘* The foundation is generally upon piles about 50 feet long, driven into the hard 
clay which overlies the rock. Next to the Hera/d Building, however, which adjoins 
it, wells were substituted, lest the shock of the pile driver close to its walls should 
cause settlements and cracks. A short cylinder, 5 feet in diameter, made of steel 
plate, was first sunk by hand, reaching below the footings of the Hera/d Building. 
Then around and inside the base of the cylinder sheet piles, about 34 feet long, 
were driven, and held in place by a ring of steel inside their upper ends. The 
material inside the sheeting was excavated and a similar steel ring was placed 
inside their lower ends. By means of wedges the lower ends of the sheeting were 
forced back into the soft clay until another course could be driven outside the lower 
ring. This operation was repeated until the excavation had reached the hard clay 
about 40 feet below the cellar. In this material the excavation was continued 
without sheeting in the form of a hollow truncated cone to a diameter of 7% feet, 
and the entire excavation was filled with concrete. The wells are spaced about 12 
feet. The loads upon them vary; some of them will carry about 200 tons 

‘‘ The material excavated was a soft, putty-like clay to a depth of 40 feet, where 
a firm clay was reached deemed capable of carrying the weight proposed.” * 


*** Foundations of High Buildings.””’ By W.R Hutton, C. E., etc. - 
gress of Architects at Chicago, 189 a‘ ; pe peat eae, ances On 


FOUNDATIONS ON COMPRESSIBLE SOILS. 57 
CAISSONS. 


64. Although caissons have been extensively used in constructing 
the foundations of bridge piers, they have as yet been used for the 
foundations of but few buildings in this country, the first instance 











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WAL Ercanoremmne Ri Cond” 


being the building for the Manhattan Life Insurance Company, near 
the foot of Broadway, New York City—Messrs. Kimball & Thomp- 
son, Architects ; Charles O. Brown, Consulting Engineer. 


58 BUILDING CONSTRUCTION. 


As it is claimed that the method there employed proved perfectly 
satisfactory, and cost only about 8 or g percent. of the estimated cost 
of the building, it is deemed of sufficient importance to merit a short 
description of the manner in which the foundations were constructed 
and the superstructure supported therefrom.* 


‘- The building occupies an area of about 8,200 square feet, and is seventeen 
stories high on Broadway and eighteen on New Street. The height from the 
Broadway curb to the parapet of the main roof is 242 feet, and the dome and tower 
rises 108 feet abc ve the parapet. All the walls, together with the iron floors and 
roof (which are very heavy), are directly supported by thirty-four cast iron col- 
umns, which sustain an estimated weight of about 30,000 tons. 


‘‘ The great height and massive metal and masonry construction impose enor- 
mous loads on the founda‘ions, amounting to as much as 200 tons for some single 
columns, and giving about 7,300 pounds per square fvot over the whole area of the 
lot. This enormous weight could not be safely carried on the natural soil, which 
is essentially of mud and quicksand to the bed rock, which has a fairly level 
surface about 54 feet below the Broadway street level. Above this rock the 
water percolates very freely, standing at a level of about 22 feet below the 
Broadway street line, and therefore making excavations below this plane difficult 
and costly. If piles had been driven as close together as the city regulations per- 
mit—z. e., 30 inches centre to centre over the whole area, about 1,323 might have 
been placed, and would have carried an average load of 45,300 pounds each, which 
was inadmissible, the statute laws of New York allowing only 40,000 pounds each 
on piles 2 feet 6 inches apart and with a smallest diameter of 5 inches. 


‘« Special foundations were therefore necessary, and it was imperative that their 
construction and duty should not jeopardize nor disturb the existing adjacent heavy 
buildings which stand close to the lot lines. On the south side the six-story Con- 
solidated Exchange Building is founded on piles which are supposed to extend to 
the rock. On the north the foundaticns of a four-story brick building rest on the 
earth about 23 feet above the rock, and were especially liable to injury from dis- 
turbances of the adjoining soil, which was so wet and soft as to be likely to flow if 
the pressure was mucn increased by heavy loading or diminished by the excava- 
tion of pits or trenches. 

‘«In view of these conditions it was determined to carry the foundations on solid 
masonry piers down to bed rock. The construction of the piers by the pneumatic 
caisson process was, after careful consideration by the architects, backed by opin- 
ions from prominent bridge engineers as to its feasibility, adopted. 


‘‘The smaller caissons were received c mplete and the larger ones in conven- 
ient sections, bolted together when necessary, and located in their exact horizontal 
positions, calked and roofed with heavy beams to form a platform, on which the 
brick masonry was started and built up for a few feet before the workmen entered 
the excavating chamber and began digging out the soil. The removal of the soil 
allowed the caissons to gradually sink to the rock below without disturbing the 
adjacent earth, which was kept from flowing in by maintaining an interior pneu- 


* The following is an abstract from a very full description, with ten illustrations, published in 
the Engineering Record of January 20, 1894. 


5Y 


FOUNDATIONS ON COMPRESSIBLE SOILS. 


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6o BUILDING CONSTRUCTION. 


matic pressure slightly in excess of the outside hydrostatic pressure due to the dis- 
tance of the bottom of the caisson below the water line. 

‘*The adjacent buildings were shored up at the outset and scrupulously watched, 
observations being made to determine any possible displacement or injury of their 
walls, which were not seriously damaged, though the pressure they exerted on the 
yielding soil tended to deflect: the caissons which were sunk within a foot of them. 
They were kept in position by excess of loading and excavating on the edges that 


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Fig. 26.—The Manhattan Life Insurance Building, New York City.—Transverse Section.* 


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tended to be highest. The caissons encountered boulders and other obstructions, 
and were sunk through the fine soil and mud at an average rate of 4 feet per day. 
No blasting was required until the bed rock was reached and leveled off under the 
edges and stepped into horizontal surfaces throughout the extent of the excavating 
chamber. Usually one caisson was being sunk while another was being prepared, 
_ there being only one time when air pressure was simultaneously maintained in two 
caissons. Generally about eight days were required to sink each caisson.” 


* Published by consent of the Engineering Record. 


FOUNDATIONS ON COMPRESSIBLE SOTLS. Gt 


The first caisson was delivered at the site April 13, 1893, and the last pier was 
completed August 13, 1893. 

‘« After the caissons were sunk to bed rock, and the surface cleared and dressed, 
the excavating chambers and shafts were rammed full of concrete, made of 1 part 
Alsen Portland cement, 2 parts sand and q parts of stone, broken to pass through 
a 24-inch ring. The superimposed piers were built of hard-burned Hudson River 
brick, laid in mortar composed of 1 part Little Giant cement to 2 parts sand.”’ 

Fig. 25 is a plan showing the piers (all of which, except P, which is built on 
twenty-five piles, are founded on caissons of the same size) and the bolsters on top 
of them, together with the girders and the columns, which are indicated by solid 
block cross sections. 

‘*Cylindrical caissons are the most convenient and economical, and would have 
been used throughout if the conditions had permitted, but the positions of the col- 
umns and the necessity of distributing the load along the building lines and other 
considerations determined the use of rectangular ones, except in four cases.”’ All 
the caissons were II feet high, made of }-inch and ?-inch plates and 6x6-inch 
angle framework, stiffened with 7-inch bulb angles, vertical brackets and rein- 
forced cutting edges. 


The columns supporting the outer side walls of the building were located so near 
the building line’as to be naar or beyond the outer edge of the foundation piers, as 
shown in Fig. 25, so that if they had been directly supported therefrom they would 
have loaded it eccentrically and produced undesirable irregularities of pressure. 
This condition was avoided and the weights transmitted to the centres of the piers 
by the intervention of heavy plate girders, which supported the columns in the 
required positions and transferred their weights to the proper bearings above the 
piers. From these bearings the load was distributed over the whole area of 
the masonry by special steel bolsters. 

Fig. 26 is a transverse section at D-H-J/, Fig. 25, showing the quadruple 
girder C, 17-18-19, and the manner in which it supports columns 23 and 33. The 
cantilever is made continuous across the building, with intermediate supports under 
columns 21 and 22. 

Pneumatic caisson foundations were also used in the foundation 
construction of the American Surety Building, New York, a full 
description of which is given in the Lugineering Record of July 14, 
1894. Caisson foundations, whether in the shape of wells or of the 
pneumatic form, should only be used under the advice or direction of 


a competent engineer. 


65. Foundations of High Buildings.—In preparing the foun- 
dations of high. buildings the same principles apply as for other 
buildings, except that the loads on the foundations being so much 
greater the footings must be proportioned with the utmost care. 


When building on firm soils it is only necessary to carefully observe 
all the precautions given in Chapter I., and on compressible soils one 
of the methods described in this chapter should be employed, always, 
however, under the advice of an experienced engineer. 


CHAPTER III. 


MASONRY FOOTINGS AND FOUNDATION 
WALLS, SHORING AND 
UNDERPINNING. 





MASONRY FOOTINGS. 


66. Footings under walls are used for two purposes: 1. To spread 
the weight over a greater area. 2. To add to the stability of the wall. 
Under buildings of only two or three stories, the latter function 1s 
generally the more important. . 

All walls should therefore have a footing or projecting course at 
the bottom of either brick, stone or concrete. 

The width of the footings should be at least 12 inches wider than 
the thickness of the wall above, and also such that the pressure per 
square foot under the footing will not exceed the safe bearing power 
of the soil or the material on which it rests. (See Section 16.) 

67. Concrete Footings.—For nearly all classes of buildings 
built on solid ground cement concrete makes probably the best mate- 
rial for the bottom footing course, especially for the money expended. 
Concrete possesses the advantage over large blocks of stone of having 
considerable transverse strength, so that when fully hardened it is 
much like a wide beam laid on top of the ground under the walls; 
and should a weak spot occur in the ground under the footing it 
would probably have sufficient transverse strength to span it if the 
spot were not very large. Concrete must also necessarily bear evenly 
over the bottom of the trenches, so that there can be no cavities, as 
is sometimes the case with stone footings. In localities where large 
blocks of granite or flagging cannot be cheaply procured, concrete 
makes much the cheapest footing. 

In stiff soils trenches for the concrete footing should be dug below 
the general level of the excavation and of the exact width of the 
footings, so that when the concrete is put in and tamped it will bear 
against the sides as well as the bottom of the trench. In sandy soils 
this of course cannot be done, and planks must be set up and held in 
place by stakes to form the sides of the trench. After the cement has 
set, but not before, the planks may be removed. 

Concrete for footings should be mixed in the proportion of 1 part 
cement to 2 of sand and 4 of stone for natural cements, and 1 to 24 


MASONRY FOOTINGS. 03 


and 54 for Portland cement. The thickness of the concrete should 
be one-fourth of its width, and never less than 12 inches, except 
under very light buildings. The concrete should be put in in layers 
about 6 inches thick. If the footing is considerably wider than the 
wall it may be stepped in by setting up plank to hold the upper lay- 
ers of concrete, or a stone footing of proper width may be placed on 
top of the concrete, as in Fig. 27. The latter is apt to give the best 
results. 

For the manner of mixing the concrete see Section 142 and specifi- 
cations in Chapter X. For width of offsets see Section 7o. 





=e sa = STS ZB 5 
fel Mend Pee “Woe ingot 5 
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Fig. 27. Fig. 28. 

68. Stone Footings.—For buildings of moderate height stone 
footings are generally the most economical, and if they are carefully 
bedded, answer as well as concrete. 

If practicable, the bottom footing course should consist of single 
stones of the full width of the footing, and the thickness of the stones 
should be about one-fourth of their width, depending much, however, 
upon the kind of stone. If stone of sufficient width cannot be 
obtained, the stone may be jointed under the centre of the wall, and 
a second course consisting of a single stone placed on top, as shown in 
Fig. 28. 

For light buildings of only one or two stories, used for dwellings or 
similar purposes, irregular shaped stones, called ‘Sheavy rubble,” are 
generally used, as shown in Fig. 29, which represents a plan of 
the footing course, the spaces between the larger stones being filled 
in with smaller stones. Each stone should be laid in mortar and the 
spaces between the stones solidly filled with mortar and broken stone. 

Under heavy buildings the footing stones should be what are called 
“dimension stones,” that is, they are roughly squared to certain 
dimensions. Dimension stones for footings may be obtained from 4 
to 8 feet in length, according to the kind of stone. The width of the 


64 BUILDING CON SLROCLION: 


stones, measured lengthways of the wall, should be at least 2 feet, or 
two-thirds the width of the footings. 

The best stones for heavy footings are: Granite, bluestone, siate 
and some hard laminated sandstones and limestones. 

69. Ledding.—As footing stones are generally very rough, being 
left as they come from the quarry, they cannot be made to bear evenly 
on the bottom of trenches | 
) without being bedded 
a Pp a He, | = either in a thick bed of 

t mortar, or, if the soil is 
sand or gravel, by wash- 
ing the sand into the 
spaces by means of a stream of water. As arule, the only safe way 
is to specify that the stones shall be set in a thick bed of cement 
mortar and worked around with bars until it 
is solidly bedded. 

70. Offsets.—The projection of the foot- 
ings beyond the wall, or the course above, isa 
point that must be carefully considered, what- 
ever be the material of the footings. 

If the projection of the footing or offset of 
the courses is too great for the strength of the 
stone, brick or concrete, the footing will 
crack, as shown in Fig. 30. 

The proper offset for each course will depend upon the vertical 
pressure, the transverse strength of the material, and the thickness of 
the course. Each footing stone may be considered as a beam fixed 
at one end and uniformly loaded, and in this way the safe projection 
may be calculated. 

Table V. gives the safe offset for masonry footing courses, in terms 
of the thickness of the course, computed by a factor of safety of 10. 


s 
ee ie 


y~ 
Hy 
¢ 


y 
4 


Sz 





Fig. 29. 





Fig. 30. 





TABLE V. 
can OFFSET FOR A PRESSURE, IN TONS PER SQUARE 
KIND OF FOOTING. eee FOOT ON THE BOTTOM OF THE COURSE, OF 
SQ. IN.*| 0,5 I 2 3 5 ro 
Bluestone Hagens. «Wiese alc eiale reve 2,700 3.6 2.6 1.8 Ea5 1.2 8 
Granites car eels ere ciclo sialaviss ele cree 1,800 2.9 aan 7.5 1.2 I FJ 
TGiMEStONE sis aatisiescce cet farsi oe .| 1,500 2.7 1.9 aie) ror 9 6 
AMASEOME.csrcisietete clvis ap isie'e sloleierersisict: 1,200 2.6 1.8 123 1.0 8 3 
Slate mr wpe ross cpersoleats «sete stent 5.400 5.0 3.6 2.5 2.2 125 1.2 
Bestshardsbricks:. ese secscle sec cece. « 1,200 2.6 1.8 123 1.0 8 5 
TPOrtlandwccsecisscser 
Concrete (o-sandy aus. «meave hie 150 0.8 0.6 0.4 
SB Pepbles: Wasiiesecaecsen 
z Rosendale 2... s05.500- 
Concrete @ SANG UW cence ccieee ese 80 0.6 0.4 0.3 Sone Sere Ane 
3 pevbies.s...c.- Baers 








ae RN es 


* Modulus of Rupture, values given by Prof. Baker in ‘‘ Treatise on Masonry Construction.”’ 


MASONRY FOOTINGS. 65 


It shouid be borne in mind that as each footing course transmits 
the entire weight of the wall and its load, the pressure will be greater 
per square foot on the upper courses, and the offsets should be made 
proportionately less. 

71. Lxample.—A 4-foot footing course of limestone transmits a 
load of 12 tons per lineal foot or 3 tons per square foot; the thick- 
ness of the course is 10 inches. What should be the width of the 
course above? 

Answer.—¥ rom the table under the column headed 3 we find the 
projection to be 1.1 times the thickness, or in this case rz inches. 
As we would have the same projection each side of the wall, the 
stone above may be 22 inches less in width, or 2 feet 2 inches wide. 
Except in cases where it is necessary to obtain very wide footings it 





Fig. 33. Fig. 34. 


is better not to make the offsets more than 6 or 8 inches, and in the 
case above it would be better to make the upper footing course 3 feet 
wide. Most building ordinances require the projection of the footings 
beyond the foundation wall to be at least 6 inches on each side. 

72. Brick Footings.—On sandy soils brick foundations. and 
footings may be used when good stone cannot be cheaply obtained. 
In Denver, Col., where the soil is a. mixture of sand and clay, very 
dry and unaffected by frost, brick foundations have been found to 
answer the purpose fully as well as stone for two and three-story 
buildings. 


66 BUILDINGICONSTRUCTLION. 


In building brick footings, the principal point to be attended to is 
to keep the back joints as far as possible from the face of the work, 
and in ordinary cases the best plan is to lay the footings in single 
courses ; the outside of the work being laid all headers, and no course 
projecting more than one-quarter brick beyond the one above it, 
except in the case of unloaded g-inch walls. The bottom course 
should in all cases be a double one. Figs. 31-34 show the proper 
arrangement of the brick in walls from one to three bricks in thick- 
ness. If the ground is soft and compressible, or the wall heavily 
loaded, the footings should be made wider, as shown in Fig. 35. For 
brick footings under high walls, or walls that are very heavily loaded, 
each projecting course should be made double, the heading course 
above and the stretching course below. 


The bricks used for footings should be the hardest and soundest 
that can be obtained, and should be laid in cement or hydraulic lime 
mortar, either grouted or thor- 
oughly slushed up, so that every 
joint shall be entirely filled with 
mortar.. The writer favors grout- 
ing brick walls, that is, using thin 
mortar for filling the inside joints, 
as he has always found it to give 
very satisfactory results. 

The bottom course of the foot- 
ing should always be laid in a bed 
of mortar spread on the bottom of the trench, after the latter has 
been carefully leveled. All bricks laid in warm or dry weather should 
be thoroughly wet before laying, for, if laid dry, the bricks will rob 
the mortar of a large percentage of the moisture it contains, greatly 
weakening the adhesion and strength of the mortar. 


Fig. 35, 


Too much care cannot be bestowed upon the footing courses of 
any building, as upon them depends much of the stability of the 
work. If the bottom courses are not solidly bedded, if any seams or 
vacuities are left in the beds of the masonry, or if the materials them- 
selves are unsound, the effects of such carelessness are sure to show 
themselves sooner or later, and almost always when they cannot be 
well remedied. Nothing is more apt to injure the reputation of a 
young architect than to have a building constructed under his direc- 
tion settle and crack, and he should see personally that no part of 
the foundation work is in any way slighted. 


MASONRY FOOTINGS. 67 


73. Inverted Arches.—lInverted arches are sometimes built 
under and between the bases of piers, as shown in Fig. 36, with the 
idea of distributing the weight of the piers over the whole length of 
the footings. This method is objectionable—first, because it is 
nearly impossible to prevent the end piers of a series from being 
pushed outward by the thrust of the arch, as shown by the dotted line, 
and second, it is generally impossible with inverted arches to make 
the areas of the different parts of the foundation proportional to the 
load to be supported. It is much better to build the piers with sep- 
arate footings, projecting equally on all four sides of the pier and pro- 
portioned to the load supported by the piers. The intermediate wall 
may either be supported by steel beams or arches, as preferred. 

In some instances, however, when building on comparatively soft 
soils, and where it 1s impracticable to use spread footings, inverted 








Fig. 36. 


arches may be advantageously used, especially when it 1s necessary 
to reduce the height of the footing to a minimum. 

If it is decided to use inverted arches, the foundation bed should 
be leveled and a footing built over the whole bed to a depth of at 
least 12 to 18 inches below the bottom of the arch. Concrete is 
- much the best material for this footing, although brick or stone may 
_ be used if found more economical. The upper surface of the foot- 
ing should be accurately formed to receive the arch. The arch 
should be built of hard brick, laid in cement mortar, and generally 
in separate rings or rowlocks, and should abut against stone or con- 
crete skewbacks, as shown in Fig. 37. 

It is better to build the arches before putting in the skewbacks, 
and for the latter 1 to 6 Portland cement concrete possesses special 


68 BOLILDING CONST ROUCLION. 


advantages, as the concrete can be deposited between the ends of the 
arches and rammed evenly and simultaneously, thus giving a solid 
and uniform bearing against the ends of the arches, tending to pre- 
vent unequal settlement and cracking. 

74. Above the concrete skewback a solid block of stone should be 
placed if it can be readily obtained. The thickness of the arch ring 
should be at least 12 inches, and heavy iron plates or washers should 
be set in the middle of the concrete skewbacks and connected with 
iron-or steel rods, to take up the thrust of the end arches. The 





Stone, Brick, orConcrete. 


Fig. 37. 


“rise”? of the arch, or distance #, Fig. 37, should be equal to from 
one-fourth to one-sixth of the span. The sectional area of the arch 
should equal the result obtained by the following formula: 


Total load on arch (in lbs.) X span 


Section of arch in sq. inches = 
8X fe X Io 





and the area of the tie rods should equal 


Total load on arch (in lbs )Xspan 


for wrought iron 
8X RX 850 lias 





and 
Total load on arch X span 
8X &X 1050 





for steel, 


the span being measured in /ee/, and the distance F 7” inches. 

The load on the arch will be equal to the span multiplied by the 
pressure per /zzea’ foot imposed on the soil. The latter will be 
obtained by dividing the load on the piers by the distance between 
centres of piers. 

75. Lxample.—It is desired to use inverted arches between the 
piers of a three-story building, resting on a soil whose bearing power 


——* 


FOUNDATION WALLS. 69 


cannot be safely estimated at over 3,000 pounds per square foo 
The piers are of stone, 4 feet long, 22 inches thick, and 14 feet apart 
from centres. Each pier supports a total load of 98,000 pounds, 
What should be the sectional area of the arch, and of the rods in end 
spans ? 

Answer.—The span of the arch will be 10 feet, and the distance 
RF about one-fifth of 10 feet, or 24 inches. The load per lineal foot 
on the soil will equal 98,o00+14, or 7,000 pounds. The footing 
under the arch must therefore be 2 feet 4 inches wide to reduce the 
pressure to 3,000 pounds per square foot. The width of the arch 
itself we will make 22 inches, or two and one-half bricks. The total 
load on the arch will equal 10X 7,000, or 70,000 pounds 

The sectional area of the arch must therefore equal 


70000 X 10 


ee ey square inches. 
8X 24X10 gore 


As the width is 22 inches, the depth must equal 35422, or 16 
inches, which will require four rowlocks or rings. 
The sectional area of the ties must equal, for wrought iron, 


70000 X IO 


pipe eee One ees lare 1nChes: 
8 X 24 X 850 7a i 


In this case it will be better to use two rods of 2.15 square inches in 
area, or say two 1#-inch rods. . 

All cast iron work in the foundation should be coated with hot 
asphalt, and the rods should be dipped in linseed oil while new and 
hot and afterward painted one heavy coat of oxide of iron or red 
lead paint. 

FOUNDATION WALLS. 


76. This term is generally applied to those walls which are below 
the surface of the ground, and which support the superstructure. 
Walls whose chief office is to withhold a bank of earth, such as 
around areas, are called retaining walls. 


Foundation walls may be built of brick, stone or concrete, the fe~- 
mer being the most common. Brick walls for foundations are only 
suitable in very dry soils, or in the case of party walls, where there 
is a cellar or basement each side of them. 

As the method of building brick foundations is the same as for any 
brick wall, it will not be described here, but taken up in the chapter 
on Brickwork. For concrete walls see Chapter XII. 


7O BUILDING! CONSTRUCTION. 


77. Stone Walls—tThe principal points to be watched in building 
a stone foundation wall are the character of the stone and mortar, 
bonding, filling of voids and pointing. 

The best stones for foundations are granites, compact sandstones, 
slates and blue shale. The less porous the stone the better it will 
stand the dampness to which it must be subjected. Asa rule lami- 
nated stones make the best wall, as they split easily and give flat and 
parallel beds. If the only stone to be had is boulders or field stone, 
they should be split so as to form good bed joints. Cobble or round 
stones should never be used for building foundation walls, and for all 
buildings exceeding three stories in height, block stone or the best 
qualities of laminated stone should be used. 

The mortar for foundation walls below the grade line should be 
made either of natural cement, or hydraulic lime, and coarse sand ; 
above grade good common lime, or lime and cement, may be used. 

The usual practice in building foundations is to use the stone just 
as it is blasted from the quarry, or, if the building is built on a ledge, 
from the foundation itself, the stone receiving no preparation other 
than breaking it up with a sledge hammer, and squaring one edge 
for the face. ‘Too great irregularity and unevenness is overcome by 
a sparing use of the stone hammer and by varying the thickness of 
the mortar joint in which the stones are bedded. ‘ The strength of 
the wall, therefore, depends largely upon the quality of the mortar 
used. 

The wall should be leveled off about every 2 feet, so as to form 
irregular courses, and the horizontal joints should be kept as nearly 
level as possible. 

When block stone is used the stones are generally from 18 inches 
to 2 feet thick and the full width of the wall. They are commonly 
roughly squared with the hammer, and but little mortar is used in the 
wall. Only in a few localities, however, are such stones obtainable 
at a price that will permit of their use, so that as a rule stone split 
from a ledge and called “rubble” is the material with which the 
architect will have to deal. 

78. Bonding.—Aside from the quality of the stone and mortar, the 
strength of a rubble wall depends upon the manner in which it is 
bonded or tied together by lapping the stones over each other. 
About every 4 or 5 feet in each course a bond stone should be used ; 
that is, a stone that will go entirely through the wall, and, by its fric- 
tion on the stones below, hold them in place. A stone that goes 
three-fourths of the way through the wall is called a three-quarter 


FOUNDATION WALLS. 71 


bond. It is usually customary to specify that there shall be at least one 
through stone in every 5 or 10 square feet of the wall, depending upon 
the character of the stone and nature of the building. Fig. 38 shows 
a portion of wall built of square or laminated stone, with through 
bond stone, & 4, and three-quarter bond stones at 4 A. A good 
three-quarter bond is nearly equal in strength to a through bond, and 
when the character of the stone will permit of the wall being built 
largely of flat stone extending two-thirds of the way through the wall, 
it will not be necessary to use more than one through stone to every 


eee 





Lf 





Fig. 38. 


ro square feet of wall. No stone should be built into the face of a 
wall with a less depth than 6 inches, although stone masons will often 
set a stone on edge, so as to make a good face and give the appear- 
ance of a large stone, when it may be only 3 inches thick. All kinds 
of stones should always be laid so that their natural bed, or splitting 
surface, will be horizontal. It is also important that the stones shall 
break joint longitudinally, as in Fig. 38, and not have several vertical 
joints over each other, as at 4 A, Fig. 39. The angles of the foun- 
dation should be built up of long stone, laid alternately header and 
stretcher, as shown in Fig. go. The largest and best stone should 
always be put in the corners, as these are usually the weakest part of 
the wall. 


7 


72 BOLLDINGSCON SLRUGZ TON. 


79. Filling of Voids.—All stones, large and small, should be 
solidly bedded in mortar, and all chinks or interstices between the 
large stones should be partially filled with mortar and then with 
small pieces of stone, or spalls, driven into the mortar with the 
trowel, and then smoothed off 
on top again with mortar. 

Many masons are apt to 
build the two faces of the wall 
with long, narrow stones and 
fill in between with dry stone, 
throwing a little mortar on top 
to make it look well. 

A horizontal section through 
such a wall would appear as 
shown in Fig. 41. Such a wall 
would require but little loading 
to cause the outside faces to 
bulge, owing to the lack of 
strength in the middle portion. 
The way in which a wall of irregular shaped stones should be built 
to get the most strength is shown in Fig. 42. 

Such a wall requires no more stone than the other, but requires 





Fig. 39. 






TAA 


SSM . 
Say aa 





NW 


i 










more /ifting and a little more use of the hammer, and these appear 

to be the real reasons why better work is not more generally done. 
80. Window Openings.—If there should be a window or door 

opening in the foundation wall, as in Fig. 43, the stones just below 


FOUNDATION WALLS. 73 


the opening should be laid so as to spread the weight of the wall under 
the opening, as shown by the stones 4 BC. If there is to be any 
great weight come upon the foundation it will be better not to build 
the window sills into the wall, but to make their length just equal to 
the width of the opening, 
or slip sills, as they are 
called, then there will be 
no danger of their break- 
ing by uneven settlement 
of the wall. 

_ Occasionally part of the 
foundation wall of a build- 
ing goes down much lower 
than the adjoining portion, 
and, as there is almost 
always a slight settlement 
in the joints of the wall, unless laid in cement the deeper wall will 
naturally settle more than the other, and thus cause a slight crack. 
This can be avoided by building the deeper wall of larger stone, so 











WILD. eet | it 


i N ees ra 


it Wa) Cities ul Sn Cl 
“eq 


Fig. 43. 





that there will be no more joints than in the other wall, or by mak- 
ing thin joints and using cement mortar. 

81. Thickness of Foundation Walls.—The thickness of the 
foundation wall is usually governed by that of the wall above, and 
also by the depth of the wall. 


74 | BUILDING CONSTRUCTION. 


Nearly all building regulations require that the thickness of the 
foundation wall, to the depth of 12 feet below the grade line, shall 
be 4 inches greater than the wall above for brick and 8 inches 
for stone, and for every additional 1o feet, or part thereof deeper, 
the thickness shall be increased 4 inches. In all large cities the 
thickness of the walls is conirolled by law. For buildings where the 
thickness is not so governed the following table will serve as a fair 


guide: 
TABLE VI._THICKNESS FOR FOUNDATION WALLS. 





DWELLINGS, HOTELS, 





Roe WAREHOUSES. 
HEIGHT OF BUILDING. 

BRICK. STONE. BRICK. STONE. 

‘Ins. ESS Lt Ins. Ins. 
WO [StOTIGS.. sa nes eee ta eres I2 or 16 20 16 20 
OL NGORUSLOTIES Rate ets then oe ere ait eee 16 20 20 24 
FGur Stories ssc ate. nto eee ee ose 20 24 24 28 
Five Storiese .. .. cis cat celistes.s enter 24 28 24 28 


Six StOHlespens sivas cre te sate see ate 24 28 28 ise 





Only block stone, or first-class rubble, with flat beds, should be 
used in foundations for buildings exceeding three stories in height. 
The footings should be at least 12 inches wider than the width of the 
walls. (See Section 66.) 

In heavy clay soils it is a good idea to batter the walls on the out- 
side, making the wall from 6 inches to a foot thicker at the bottom 
that it is at the top, and plastering the outside with cement. (See 
Fig. 3, Section 10.) 

RETAINING WALLS. 

82. A retaining wall is one that is built to hold up a bank of 
earth, which is afterward deposited behind it. Retaining walls dif- 
fer from foundation walls, in that the latter support a superstructure 
whose weight is generally sufficient to overcome the thrust of the 
earth against the wall. A retaining wall, on the other hand, depends 
upon its own stability to resist the earth pressure. 

True retaining walls are seldom designed by the architect, as the 
only place for which he would be likely to plan such walls is for the 
support of terraces, etc. 

Area walls, it is true, generally serve as retaining walls, but as they 
are usually braced by arches or cross walls from the building wall, 
they do not require the same thickness as a retaining wall proper. 
Several theoretical formule have been evolved by writers on engi- 
neering subjects for computing the necessary thickness and most 


RETAINING WALLS. 45 


economical section of retaining walls, but so many variable condi- 
tions enter into the designing of such walls, such as the character and 
cohesion of the soil, the amount the bank has been disturbed, the 
manner in which the material is filled in against the wall, etc., that 
little confidence is placed in these theoretical formulz by practical 
engineers, and they appear to be guided more by empirical rules, 
derived from experience. 


The cross section that appears to be most generally approved for 

retaining walls, particularly in engineering work, is shown in Fig. 44. 
The wall may either be built plumb, as shown, or inclined toward 

the bank. The latter method is generally considered as securing 

_ greater stability, although it is 
open to the objection that the 
water which runs down the face 
of the wall is apt to penetrate 
into the inclined joints. 


—_-- 


Retaining walls should be 
built only of good hard split or 
block stone;*laid in cement mor- 
tar and carefully bonded, to pre- 
vent the stones from sliding on 
the bed joints. 

The thickness of the wall at 
the top should be not less than 
18 inches, and the thickness, a, 
just above each step should be 
from one-third to two-fifths of 
the height from the top of the 
wall to that point. 

If the earth is banked above 
the top of the wall, as shown by the dotted line, Fig. 44, the thick- 
ness of the wall should be increased. A thickness equal to one-half 
of the height will generally answer for a height of embankment equal 
to one-third that of the wall. 

The outer face of the wall is generally battered, or sloped outward, 
about 1 inch to the foot. 

Stepping the wall on the back increases the stability by bonding 
the wall into the material behind and having its weight increased by 
the weight of the soil resting upon the steps. 

If built upon ground that is affected by frost or surface water, the 


——— ——_—__ 


* Or Portland cement concrete with twisted iron bars. 





Fig. 44. 


76 BUILDING CONSTRUCTION: 


footings should be carried sufficiently below the surface of the ground 
at the base of the wall to insure against heaving or settling. 

If the ground back’ of the wall slopes toward the wall a cement 
gutter should be formed behind the coping and connected with a 
drain pipe to carry off the surface water. The back of the wall and 
tops of steps should be plastered with cement to the depth of at least 
3 or 4 feet. 

AREA WALLS. 

83. Areas are often excavated outside the foundation walls of 
buildings to give light or access to the .basement, and require to be 
surrounded by a wall to retain the bank and present a neat appearance. 

Such wails should be built of stone, as a stone wall offers greater 
resistance, when the mortar is green, to sliding on the bed joints than 
a brick wall. 

In making the excavation the bank should be disturbed as little as 
possible, and in filling against the wall the soil should be deposited 

7 in layers and well tamped, and not 
dumped carelessly behind the wall. The 
v=. filling should also be delayed until the 
mortar has had time to harden, or else 
the wall should be well braced. 

Area walls are commonly built in the 
same manner as foundation walls and of 
a uniform thickness, generally about 20 
inches for a depth of 7 feet. If more 
than 7 feet in height the wall should have 
a batter on the area side and should be 
increased in thickness at the bottom, so that the average thickness of 
the wall will be at least one-third of the height, unless the wall is 
braced by arches, buttresses or cross walls. 

Area walls sustaining a street or alley should be made thicker than 
those in an open lot. 

When an area wall is more than ro feet long it is generally prac- 
ticable to brace it from the basement wall by arches thrown across 
from one wall to the other, as shown in Fig. 45. When this cannot 
be done the wall should be stiffened by buttresses about every ro feet. 


VAULT WALLS: 


84. In large cities it is customary to utilize the space under the 
sidewalk for storage or other purposes. This necessitates a wall at 
the curb line to sustain the street and also the weight of the sidewalk. 





AREA AND VAULT WALLS. ti 


Where practicable, the space should be divided by partitica walls 
about every 10 feet, and when this is done the outer wall may be 
advantageously built of hard brick in the form of arches, as shown in 
Fig. 46. 

The thickness of the arch should be at least 16 inches for a depth 
of 9 feet, and the “‘rise”’ of the arch one-sixth of the span. 

If partitions are not practicable, each sidewalk beam may be sup- 
ported bya heavy I-beam column, with either flat or segmental arches 
between, as shown in Fig. 47. 

This latter method is more economical of space than any other, 
and where steel is cheap is about as economical in cost. 


SUPERINTENDENCE OF FOUNDATION WORK. 
85. The first work on the foundations will be putting in the 
footings. 





Fig. 46. Fig. 47. 


If the footings are of concrete, an inspector should be put on the 
work to stay during the entire working hours, and see that every batch 
of concrete is mixed in exactly the proportion specified, and that the 
aggregates are broken to the proper size and the cement all of the 
same brand and in good condition. There is no building operation 
that can be more easily “skimped” without detection than the 
making of concrete, and the only way by which the architect can be 
sure that his specifications have been strictly followed is by keeping 
a reliable representative constantly on the ground. The inspector 
should also see that the concrete is put in to the full thickness shown 
on the drawings, and that it is leveled and tamped every 6 inches 
in depth. 

Should water be encountered in the trenches, it should be collected 
in a shallow hole and removed by a pump or drain, as explained in 


78 BUILDING CONSTRUCTION. 


Section 31. Very often, when the foundation rests on the top of a 
ledge, underlying gravel or clay, running water will be encountered in 
the trenches in too great a volume to be readily removed. In such 
a case, the flow of the water should be intercepted by a drain and 
cesspool, and a tight drain carried from the latter to a sewer or toa 
dry well below the foundation of the building. 

Concrete footings for piers not more than 4 or 5 feet square 
may be built, where there is running water, by making large bags of 
oiled cotton and sinking them in the pit, filling the concrete into 
them immediately. The water will probably rise around the bag, but 
if the latter keeps the water away from the concrete until the cement 
has had time to set, it will have answered its purpose. Water does 
not injure concrete, or mortar made of cement, after it has begun to 
harden, but if freshly-mixed concrete is thrown into water the water 
separates the cement from the sand and aggregates, the cement mixing 
with the water and floating away, while the sand and stone drops to 
the bottom. For this reason concrete should never be thrown into 
trenches containing water. 

86. If the footings are of stone the presence of water does not do 
as much harm, provided the water can be drained so as not to attain 
a greater depth than 3 or 4 inches. Sometimes the bottom of 
the wall is used as a drain for collecting the seepage water, and the 
trench is partially filled with stones laid without mortar, as explained 
in Section ro. 

For heavy buildings, however, the footings should be solidly bedded 
in cement mortar when the trenches are reasonably dry, and when 
this is not the case, in sand or fine gravel. An irregular footing 
stone can often be bedded more solidly by piling fine sand around 
it and then washing the sand under the stone with water, than it can 
in cement mortar. The former method, however, takes more time, 
and would seldom be employed where mortar could be used as well. 

As stated in Section 72, too much care cannot be bestowed upon 
the footing courses of any building, and there is no portion of the 
building that needs closer inspection than the footings and foundation. 

Before the masons commence actual operations the architect 
should inspect all materials that have been delivered, to see that they 
are of the kind and quality specified. 

The mortar, together with the sand, cement or lime, should be par- 
ticularly examined, to see that the mortar has the proper proportions 
of cement or lime, and is well worked; that the cement or lime is 
fresh and all of the kind or brand specified; and that the sand is 


FOUNDATION WALLS—SUPERINTENDENCE. 179 


clean and sharp. The building of the foundation wall should also 
be carefully watched to see that the wall is well tied together with 
plenty of three-quarter and through bond stones, and that the inside 
is solidly filled with stone and mortar. 

The superintendent must also examine the wall occasionally to see 
that it is built straight and plumb, and that the general bed of the 
courses is horizontal. 

When inspecting stonework already built, but which has not had 
time for the mortar to harden, a light steel rod, about 3%; inch in di- 
ameter and 4 or 5 feet long, will be found useful. If the rod can be 
pushed down into the centre of the wall more than 18 inches or 2 
feet in any place it shows that the stones have not been lapped over 
each other, and if this can be done in several places the inspector 
should order the wall taken down and rebuilt. The rod will also 
indicate to a considerable extent whether or not the stones in the 
centre of the wall have been well bedded, as if they have not they 
will rock or tip when struck with the rod. 

The inspection of a foundation wall cannot be too thorough, as there 
is nothing that causes an architect so much trouble as to have settle- 
ments in the foundations of his buildings. 

87. Filling in.—In buildings where the cellar floor is 6 feet or 
more below the ground level the trenches behind the walls should not 
be filled in until the floor joists are on and the wall built 6 feet or 
more above them, or until the walls are solidly braced with heavy 
timbers, otherwise the wall may be sprung by the pressure of loose 
dirt. In heavy clay soils it is a good idea to fill in back of the wail 
with coarse gravel, stone spalls and sand, as frost will not “heave” 
them as it does clay. 

Holes for Soil and Supply Pipes.—In thick walls, and when 
built of heavy stone, the architect should locate the position of the. 
soil and supply pipes, and see that openings are left in the proper 
places for the pipes to pass through the wall. 


80 BOULLDINGACONSTRUGCALON, 


DAMPNESS IN CELLAR WALLS. 


88. In many localities it is necessary to guard against dampness in 
cellar walls, particularly in buildings where the basement is used for 
living rooms or for storage. There are several devices for pre- 
venting moisture from entering the walls, one class being in the nature 
of applications to the outside of the wall and the other being con- 
structive devices. 


Where only surface water is to be provided against, and the 
ground is not generally saturated with water, coating the outside of 
the wall with asphalt or Portland cement will, in most cases, prove a 
preventative against dampness. 


Asphalt, applied to the outside of the wall while boiling hot, is 
generally considered as the most lasting and durable of all coatings. 
To insure perfect protection, the wall should have been built as care- 
fully as possible, the joints well 
pointed and the whole allowed to 
get dry before the coating is 
applied. 












Cay . 
EME PORT The asphalt should be applied 
+. ar) ensayo: : 5 

al ig B29 o § O'- in two or more coats and carried 


t/a AA ak 
ee ay eee aaes 
iat oad we Bi 
ay we tee ; 


down to the bottom of the foot- 
ings. 





If the soil is wet and generaily 
saturated with water, moisture is 
' apt to rise in the wall by absorp- 
tion from the bottom. To prevent 
this, two or three thicknesses of 
asphaltic felt, laid in hot asphalt, 
ae should be bedded on top of the 
footings, just below the basement 
floor, as shown by the heavy line, 
Fig. 48. 

Portland cement may be used in place of asphalt if the ground is 
not exceeding damp, but if it is often saturated with water asphalt 
should be used. The objections to Portland cement are that it is 
easily fractured by any settlement of the walls, and being to some 
degree porous, suffers from the action of frost. 

Common coal tar is also often used for coating cellar walls; it 
answers the purpose very well for a time, but gradually becomes brit- 
tle and crumbles away. 


DAMPNESS IN FOUNDATION WALLS, oP 


89. Of the constructive devices, the simplest is to make the exca- 
vation about 2 feet larger each way than the building, so that there 
will be about a foot or to inches between the bottom of the bank 
and the wall, as shown in Fig. 48. A V-shaped tile drain should be 
placed.at the bottom of this trench after the wall is built and con- 
nected with a horizontal drain, carried some distance from the 
building. 

The trench should then be filled with cobbles, coarse gravel and 
sand. If the top, for a distance of about 2 feet from the building, is ~ 
covered with stone flagging or cement, it will assist greatly in keeping 
the walls dry. 

By draining the soil in this way, and also coating the wall with 
asphalt or concrete, a perfectlydry wall will in most cases be insured 

For greater protection of the basement from dampness, the base- 
ment walls should be lined with a 4-inch brick wall with an air space 
between the main wall and the lining, or an area should be built all 
around the outside walls. 


WINDOW AND ENTRANCE AREAS. 


90. These features, although not strictly a part of the foundations, 
are intimately connected with them, and are generally included in 
the same contract. 

The thickness and bracing of area walls has already been consid- 
ered (see Section 83). The materials and workmanship of the walls 
should bé the same as in the foundation walls. 


Window areas intended for light and ventilation should be of ample 
size, so as not to obstruct the light more than possible. 


For small cellar windows sunk not more than 2 feet below the 
grade line, a semicircular area with a g-inch brick wall will give the 
greatest durability for the least cost. If the area is 3 or 4 feet 
deep, and as many in length and width, the thickness of the wall 
should not be less than 12 inches for brick and 18 inches for stone. 

Area walls should be coped with stone flagging, set in cement, the 
edge of the flagging projecting r inch over the face of the wall. If 
- flagging cannot be obtained without excessive expense the top of the 
_ wall should be covered with 1 to 1 Portland cement mortar, about 2 
inch thick. Freestones and all porous stones are unsuited for area 
or fence copings. 

Drainage -—The bottom of the area should be carried at least 6 
inches below the window sill and shou!d be formed of stone flagging 
or of brick laid in cement. Beneath the bottom of the area a small 


PS las BUILDING CONSTRUCTION. 


cesspool or sand-trap (say 8 inches square) should be built, which 
should be connected by a 3-inch drain pipe with the main drain. A 
cast iron strainer or drain plate should be set over the cesspool, flush 
with or a little below the paving,so that it can be readily removed 
and the cesspool cleaned. The footings of the area walls should be 
started as deep as the bottom of the cesspool, both being below the 
frost line. | 







y 


i DT= 


WA 
7 Zhai i 
2 ZA SF Can Vrain. 
Ran BZ Azer, aN 
Zahn. GF We 


Fig. 49. 











91. Entrance Areas.—All area steps, wher practicable, should be 
of stone, or of stone and brick combined.* When the soil is hard and 
compact and not subject to heaving by frost, a small set of steps may 
be economically built by shaping the earth to the rake of the steps and 
building the steps directly on the earth, laying two courses of brick, in 
cement, for the risers, and covering with 2-inch stone treads, as shown 





Fig. 50. 


in Fig. 49. All parts of the steps should be set in cement, and well 
pointed, and the ends of the treads should be built into the side walls. ’ 

If the area is 6 feet or more in depth, or if the soil is sandy or a 
wet clay, then the area must be excavated beneath the steps and 
entirely surrounded by a wall. The steps may be formed of 2-inch 
stone risers and treads, or of solid stone, the ends in either case being 
supported by the side walls. If of solid stone the front of each step 





* Or of concrete and twisted iron. (See page 369a ) 


VAULTS AND AREAS. 83 


should rest on the back of the stone below it, as shown at 4, Fig. 
50. If built of treads and risers they may be arranged either as shown 
at Bor C. The arrangement shown at Z is the strongest. 


If the steps are more than 5 feet long a bearing wall or iron 
string should be built under the middle of the steps. 


Stone steps should always be pitched forward about 4 of an inch 
in the width of the tread. 


In many localities plank steps, supported on plank strings, will last 
for a long time if the ground is excavated below them and the area 
walled up all around, and when they decay it is a small matter to 
replace them. 


The platform at the bottom of the steps should be of stone or 
brick, set at least 4 inches below the sill of the door giving entrance 
to the building, and should be provided with cesspool, plate and drain, 
as described in Section go. 

All outside stone steps, fence coping, etc., should be set on a foun- 
dation carried at least 2 feet below grade, and in localities affected 
by frost below the freezing line. 


92. Vaults are often built under entrance steps and porches, the 
walls of the vault forming the foundation for the steps and platform. 
The roof of the vault is generally formed of a brick arch or vault, two 
rowlocks in thickness, with the stone steps set in cement mortar on 
top of the arch. 

Vaults under sidewalks may either be arched over with brick, the 
top of the arch leveled off with sand, cinders or concrete, and the 
sidewalk laid thereon, or the sidewalk itself, if of large stone flags, 
may be made to form the roof of the vault. In the latter case the 
joints of the stone slabs are closely fitted and often rebated, then 
caulked-with oakum to within about 2 inches of the top and the 
remaining space filled with hot asphalt or asphaltic mastic. This will 
make a tight job for a time, but in the course of two or three years 
the joints will need to be cleaned out and refilled. 

Any form of fireproof floor construction may also be used for cov- 
ering sidewalk vaults and a cement sidewalk finished on top of it. 
This probably makes the best walk and the most durable construc- 
tion, with a comparative slight thickness. 

In San Francisco it is very common to build the sidewalks of 
cement, with steel tension bars or cables imbedded in the bottom, so 
that the same construction answers both for the walk and for cover- 
ing the vault. 


84 BUILDING CONSTRUCTION. 


If brick arches, covered with sand, and a stone or brick pavement 
are used, the top of the arch should be coated with hot asphalt. 


PAVEMENTS. 


93. Although these do not come under the heading of founda- 
tions. they are more nearly elated to that class of work than to any 
other, and may therefore be described here. 

Pavements may be made either of thin slabs of stone, called flag- 
ying, of concrete, finished with Portland cement, or of hard bricks 
made especially for the purpose. 

When large slabs of stone can be economically obtained, they make, 
in the long run, the most economical pavement, and one that is about 
as satisfactory as any. 

A smoother pavement may be made with cement, and one that will 
be practically imperishable, but should there ever be occasion tc cut 
through the pavement, or to change the grade, the cement and con- 
crete must be destroyed, while the stone flagging can be taken up and 
relaid, either in the same place or 
used somewhere else. A stone side- 
sxvpremy Walk can also be repaired easier than 
Te *SCement either of the others. 
oe Stone Pavements.—As a rule only 
stones that split with comparatively 
smooth and parallel surfaces can be economically used for pavements, 
for, if the surface of the stone has to be dressed, it will generally be 
more economical to use concrete and cement or hard bricks. 

For yards and areas, flagging from 2$ to 3 inches thick is com- 
monly used, the edges of the stones being trimmed so that the stones 
will be aaa rectangular, and the joints between them straight 
and from ¢ to # inch in width. 

The tree should be laid on a bed of sand not less than 2 inches 
thick, and the edges should be bedded in cement, as shown in Fig. 
51, the cement extending some 3 or 4 inches under the stone. On 
completion the joints should be thoroughly filled with 1 to 1 cement 
and fine sand, and struck smooth with the trowel. 

In localities where the soil is dry and not affected by frost, as in 
Colorado, New Mexico, etc., the cement is generally omitted entirely. 
the stones being simply bedded’ in sand and the joints filled with fine 
sand. 

This answers very well in those localities, but after a time grass 
and weeds commence to spring up through the joints in yards and 






PAVEMENTS. 85 


private walks, so that for first-class work bedding in cement should 
be specified. 

Stone sidewalks are generally laid on a bed of sand, with the joints 
in the better class of work bedded in cement. The stones, when 5 
feet long, should be at least 3 inches thick, and if 8 feet long, 5 or 6 
inches thick. The best sidewalks are laid in one course, unless 
exceptionally wide. 

In localities where the ground is affected by frost, as it is in most 
of the Northern States, the stones, if merely laid on a bed of sand, 
are sure to become displaced and out of level within one or two 
years. To prevent this, flagging stones, in front of business build- 
ings at least, should have a solid support at each end. 













f S Y) 1s — 
Ts a Cie Pe ay, : 
Ses Vx ey Tig SIA, Foundation 


Zyl ae 
bine, 


Fig. 52. 


Fig. 52 shows the manner in which this is generally provided, and 
also the way in which the curb and gutter is supported. The curb- 
stone should be at least 4 inches thick, and on business streets 6 
inches. | 

The dwarf wall should be about 14 or 16 inches thick and carried 
below the frost line. 

If the sidewalk is laid in two courses a slight wall of brick or stone 
should also be built under the middle of the walk to support the but- 
ting ends of the stones. 

94. Cement Walks.—Cement sidewalks are extensively laid in 
the Western States, even in localities where excellent flagging stone 
is abundant and cement rather dear. 

The cement walks are preferred on account of the obeth and even 
surface which they give. When properly laid they are also very dur- 
able. Cement walks, however, should only be laid where there is no 
danger of the grade being altered, and after the ground has become 
thoroughly settled and consolidated. 

The durability of the walk depends principally upon the thickness 
of the concrete and the quality of the cement. 

Only the best Portland cement should be used for the finishing, 


86 BOLILDING CON SL RUCTION. 


although natural cements are sometimes used for the concrete. Port- 
land cement throughout, however, is to be preferred. 


For first-class work cement walks should be laid as follows: 


The ground should be leveled off about ro inches below the fin- 
ished grade of the walk and well settled by tamping or rolling. On 
top of this a foundation 5 inches thick should be laid of coarse 
gravel, stone chips, sand or ashes, well tamped or rolled with a 
heavy roller. The concrete should then be prepared by thoroughly 
mixing 1 part of cement to 1 part of sand and 3 of gravel, in the dry 
state, then adding sufficient water from a sprinkler to make a dry 
mortar. The concrete should be spread in a layer from 3 to 4 inches 
thick, commencing at one end, and should be thoroughly tamped. 
Before the concrete has commenced to set the top or finishing coat 
should be applied, and only as much concrete should be laid at a 
time as can be covered that day. If the concrete gets dry on top the 
finishing coat will not adhere toit. The top coat should be prepared 
by mixing t part of high grade Portland cement with 1 part of fine 
sand, or 1 part clean, sharp, crushed granite (the latter is the best). 
The materials should be thoroughly mixed dry, and water then added 
to give the consistency of plastic mortar. It should be applied with 
a trowel to a thickness of 1 inch and carefully smoothed and leveled 
on top between straight-edges laid as guides. Used in the above pro- 
portion, one barrel of Portland cement will cover about 40 square 
feet of concrete. After the walk is finished it should be covered with 
straw to prevent it drying too quickly. 


For brick paving see Section 381. 


SHORING, NEEDLING AND UNDERPINNING. 


95. The direction of these operations when required is generally 
left to the contractor, as the responsibility for the successful carry- 
ing out of the work devolves upon him. 

The architect will be wise, however, when such operations are 
being done in connection with work let from his office, to see 
that proper precautions are taken for safety, and that all beams or 
posts have ample strength for the loads they have to support. When 
heavy or difficult work has to be done, it should, if possible, be 
intrusted to some careful person who has had experience in that class 
of work, as it is almost a trade by itself. 


Shoring is supporting the walls of a building by inclined posts or 
struts, generally from the outside, while its foundations are being car- 


SHIRING AND UNDERPINNING. 87 


ried down, or while the lower portion of the wall is being removed 
and girders and posts substituted. 

The usual method of shoring the walls of buildings not exceeding 
three stories in height, especially when done for the purpose of hold- 
ing up the walls while being underpinned, is shown in Fig. 53. 

The props or shores are inserted in sockets cut in the wall, with 
their lower ends resting on a timber crib supported on the ground. 
At least two sets of shores should be used, one to support the wall as 
low down as possible and the other as high up as possible. The lat- 
ter shores should not have a spread at the bottom of more than one- 
third of their height. The platform should be made large enough so 
as not to bring too great a pressure on the ground, and the shores 
should be driven into place by oak or steel wedges. 

The shores should be spaced according to the height and thick- 
ness of the wall, and all piers and chimneys should be shored. Gen- 
erally a spacing of 6 feet between the shores will answer. 

Only a part of the foundation should be removed at a time, and 
as soon as three sets of shores are in place the wall should be under- 
pinned, as described in Section 97. As fast as the wall is under- 
pinned the first set of shores should be moved along, always keeping 
two sets in place, and working under or with one set. 

Shoring may often be successfully employed for holding up the 
corner of a building while a-pier or column is being changed, and 
sometimes when the lower part of the wall is to be removed and a 
girder slipped under the upper portion. In the latter case, however, 
needling is generally more successful and attended with less risk. 

96. Needling is supporting a wall, already built, on transverse 
beams or needles placed through holes cut in the wall and supported 
at each end either by posts, jackscrews or grillage. Atleast one end 
of the horizontal beam should be supported by a jackscrew. 

Wherever a long stretch of wall is to be built up at one time, and 
there is working space on each side of it, needling should be 
employed. | 

The beams must be spaced near enough together so that the wall 
will not crack between them, and the size of the beams carefully pro- 
portioned to the weight of the wall, floors, etc. In very heavy build- 
ings steel beams should be used for the needles, and they should be 
spaced not more than 2 feet apart. In three or four-story buildings 
the needles may be of large timber and spaced from 4 to 6 feet apart. 
Each chimney or pier should have one or more needles directly 
under it. 


&8 BULEDING CONSTRUCTION. 


When the first story walls or supports are to be removed, the beams 
or needles are usually supported on long timbers having a screw 
under the lower end; or, if the wall is very high or thick, a grillage 
of timber is built up and the jackscrews are placed on top of the 
grillage, the ends of the needles resting on a short beam supported 
by two screws, in the manner shown in Fig. 54. 

When it is desired to remove the first story wall of a building for 
the purpose of substituting posts and girders, or for rebuilding the 
wall, holes should be cut in the wall from 4 to 6 feet apart, accord- 
ing to the weight to be supported and the quality of the brick or stcne 
work, and at such a height that when the needles are in place they 
will come a few inches above the top of the intended girder. Solid 
supports should then be provided for the uprights, the needles put 
through the wall, and posts, having screws in the lower ends, set 
under them, the base of the screws resting on the solid support pre- 
viously provided. If the needles do not have an even bearing under 
the wall, iron or oak wedges should be driven in until all parts of the 
wall bear evenly on the needles. The jacks should then be screwed 
up until the wall is entirely supported by the needles, care being 
taken, however, not to raise the wall after the weight is on the needles. 

The wall below may then be removed, the girder and posts put in 
place, and the space between the girder and the bottom of the wall 
built up with brickwork, the last course of brick or stone being 
made to fit tightly under the old work. The needles may then be 
withdrawn and the holes filled up. 

97. Underpinning is carrying down the foundations of an exist- 
ing building, or, in other words, putting a new foundation under the 
old ones. 

New footings may generally be put under a one or two-story build- 
ing resting on firm soil without shoring or supporting the walls above, 
the common practice being to excavate a space only 2 to 4 feet long 
under the wall at a time, sliding in the new footing and wedging up 
with stone, slate, or steel wedges. 

Where the underpinning Is to be 3 feet high or more, or where the 
building is several stories in height, the walls should be braced or 
supported by shores or needles. 

The usual method of underpinning the walls of buildings where a 
cellar is to be excavated on the adjoining lot is shown in Fig. 53. 

Pits should first be dug to the depth of the new footing, and a tim- 
ber platform built as shown; the shores should then be put in place 
and wedged up with oak wedges. 


SHORING AND UNDERPINNING. 89 





Us Ui MET 
ELEVATION 
Fig. 53. 


Sections about 3 feet wide between the shores should then be exca- 
vated under the wall, new footing stones laid, and the space between 
the new and old footings filled with brick or stone work. Where the 
height between the new and old footings does not exceed 5 feet, 
granite posts, if available, offer special advantages for underpinning. 


go, BOILDING CONSTRUCTION. 


They should be from 12 to 18 inches wide on the face and of a thick. 
ness equal to that of the wall; they should be cut so as just to fit 
between the new and old work, and with top and bottom surfaces 
dressed square; they should be set in a full bed of Portland cement 
mortar, and the top joint also filled with mortar and brought to a 
bearing with steel wedges. 

If granite posts are not available good flat stone or hard brick laid 
in cement mortar may be used instead, wedging up under the old 
wall with pieces of slate driven into the upper bed of cement, or with 
steel wedges. Under heavy walls the latter only should be used. If 
the bottom of the old footings is of soft brickwork, pieces of hard flag- 





ging, with a full bed of cement mortar, may be placed under them, 
and the wedges driven under the flagging so as to bring the latter 
“hard up” under the old work. The portions of wall between these 
sections should then be underpinned in the same way and the shores 
moved along. | 

Where granite posts are used they may be placed 3 feet apart and 
the space between built up with flat rubble or hard brick, wedged up 
under the old wall with slate. 

If the soil under the old building is sufficiently firm, so that it will 
not cave or “run away,” and there is working space beneath the 
lower floor, the ground may be leveled off, a platform of plank and 
timbers placed on top of it, and needles used for supporting the wall, 


SHORING AND UNDERPINNING. gt 


as shown in Fig. 54. Where needles are used all of the underpin- 
ning under the portion of wall supported may be put in at the same 
time. 

The underpinning should be done as quickly as possible after tne 
shores or needles are in place, so as not to require their support for a 
longer time than necessary. The needles or shores should, however, 
not be removed until the cement has had time to set. 


98. Chicago Practice. 


In building the modern tall office building in Chicago the foundations generally 
have to go below those of the adjacent buildings, and, the ground being compress- 
ible, new party wall foundations are almost invariably required. The consequence 
is that the old walls have to be supported while the new foundation is being put 
under them. This is usually done by means of steel needles placed from 12 to 24 








18 "brick wall 
1 Floor 


1 Floar | } 









re ack Screws. 


o < LB 
ee 28/7 


CVVCCCCCCJJU0:; 


Fig. 55. 











Columns similar to thes. 
to be provided when neu 
building is put upon thi's 
side of party wall, 






NM 






WSS 





N 


inches apart, their ends resting on long beams placed parallel with the wall and 
supported by jackscrews. Very often an entire wall is supported in this way, sev- 
eral hundred jackscrews being required for the purpose. 

In erecting buildings of skeleton construction it is often impracticable to remove 
the old wall, and the new building is supported by iron columns placed against the 
wall and resting on a new foundation put in under the old one. In building the 
New York Life Building in Chicago such was the case, and the adjacent wall was 
held up by jackscrews, as shown in Fig. 55, which were inserted to keep the wall 
in place during the settlement of the new work. As the new foundations settled 
the jacks were screwed up, so as to keep the old wall in its original position. In 
this case the jacks were left in place. 


99. Bracing.—Where buildings have been built with a party 
wall, and one of the buildings is torn down, leaving the adjacent 


92 BUILDING CONSTRUCTION. 


walls unsupported, they should be protected from falling by spreading 
braces or inclined shores, according to special conditions. 

Where there is a building on the other side of the vacant lot, and 
within 40 or 50 feet, the walls of both buildings may be best sup- 
ported by spreading braces, after the manner shown in Fig. 56. 

If the distance between the buildings does not exceed 25 feet, the 
braces may be arranged as shown at 4 or B. If more than 25 feet, 
the braces must be trussed in a manner similar to that shown at C. 

[Iron or steel rods are preferable for the vertical ties, as they 
can be screwed up, and 
any sagging caused by 
shrinkage in the joints 
overcome. | 

If the buildings are 
very high every other 
story should be braced. 
The ends of the braces 
or trusses must be sup- 
ported vertically, so that 
they will not slip down. Where there are offsets in the wall these 
may serve for a vertical support; if there are no offsets, then the 
braces should be supported by vertical posts, starting from the foun- 
dation, or sockets might be cut in the wall and corbels let in and 
bolted through from the inside. 

A truss should be placed opposite the fronts, and should be propor- 
tioned so as to resist the thrust from any arches there may be in the 
front. The braces should be about 8x8 or 1oxto inches in size, 
with 6x12 uprights against the wall, the ends of the braces being 
mortised into the uprights. 

If there is no wall opposite the building to be braced, then inclined 
braces must be used, arranged in a similar manner to the shores 
shown in Fig. 53, only with a greater inclination. The ends of the 
braces should be brought to a bearing by oak wedges. 








Fig. 56. 


CHAPTER IV. 


LIMES, CEMENTS AND MORTARS. 


There is hardly any material used by the architect or builder upon 
which so much depends as upon mortar in its different forms, and it 
is important that the architect should be sufficiently familiar with the 
different kinds of limes and cements to know their properties and in 
what kind of work each should be used. He should also de able to 
judge of the quality of the materials with sufficient accuracy to pre- 
vent any that is actually worthless from being used, and should have 
some knowledge of mortar mixing. 

Ioo. Lime.—Common lime, sometimes called quicklime or caus 
tic lime, is produced by the calcination (or heating to redness) of 
limestones of varying composition. ‘This is done by burning the stone 
in a kiln with an oviod vertical section and circular horizontal sec- 
tion. The broken stone and fuel (generally coal) are put in in layers, 
the fire lighted at the bottom, and as the lime drops to the bottom 
new layers of stone and coal are put in at the top, so that th2 kiln 
may be kept burning for weeks at a time. The limestones from 
which limes and cements are produced differ greatly in their compo- 
sition, ranging from pure carbonate of lime, such as white chalk or 
marble, to stones containing Io per cent. or more of impurities, such 
as silica, alumina (clay), magnesia, oxide of manganese and traces of 
the alkalies. The quality of the limé will consequently depend much 
upon the percentage of impurities contained in the stone from which 
it is made. Lime is manufactured in nearly every State in the 
Union, each locality generally producing its own supply. 

There is considerable difference, however, in the limes of different 
localities, and before using a new lime the architect should make 
careful inquiries regarding its quality, and if it has not been much 
used it would be better to procure a lime of known quality, at least 
for plastering purposes ; for common mortar it is not necessary to be 
50 particular. 

In most parts of New England lime is sold by the barrel, but in 
many parts of the country it is sold in bulk, either by the bushel or 
by weight. 


94 BUILDING CONSTRUCTION. 


Io1I. Characteristics of Good Lime.—Good lime should 
possess the following characteristics: 1. Freedom from cinders and 
clinkers, with not more than ro per cent. of other impurities. 2. It 
should be in hard lumps, with but little dust. 3. It should slake 
readily in water, forming a very fine, smooth paste, without any resi- 
due. 4. It should dissolve in soft water. 

There are some limes which leave a residue consisting of small 
stones and silica and alumina in the mortar box, after the lime is 
drained off. Such limes may answer for making mortar for building 
purposes, but should not be used for plastering if a better quality of 
lime can be procured. 

102. Slaking and Making into Mortar.—The first step in 
the manufacture of lime mortar consists in the s/aking of the lime. 
This is generally done by putting the lime in a water-tight box and 
adding water either through a hose or by pails, the amount of water 
depending upon the quality of the lime. Lime such as is sold in New 
England requires a volume of water equal to two and one-half to 
three times the volume of the lime. The water is rapidly absorbed 
by the lime, causing a great elevation of temperature, the evolution of 
hot and slightly caustic vapor, and the bursting of the lime into pieces, 
and finally the lime is reduced to a powder, the volume of which is 
from two and a half to three and a half times the volume of the orig- 
inal lime. In this condition the lime is said to be slaked and is ready 
for making into mortar. The Thomaston and Rockland (Maine) 
lime, as also most other limes sold in New England, slake without 
leaving a residue, and the mortar is made by mixing clean, sharp 
sand with the slaked hme in the proportion of 1 part of lime to about 
5 of sand by volume. Practically the proportion of sand is seldom, 
if ever, measured, but the sand is added till the person mixing the 
mortar thinks it is of the proper proportion. For brickwork over a 
certain proportion of sand cannot well be added, for if there is too 
much sand in the mortar it will stick to the trowel and will not work 
easily. With stonework the temptation is always to add too much 
sand, as sand is generally cheaper than lime. The architect or super- 
intendent should take pains to make himself familiar with the appear- 
ance of good mortar, so that he can readily tell at a glance if it has 
too much sand. Mortar that contains a large proportion of lime is 
said to be vzch; if it has a large proportion of sand and works hard it 
is said to be s¢f, and to make it work more readily it 1s tempered by 
the addition of water. Tempered mortar looks much richer than 
stiff mortar, though it may not be so. If the mortar slides readily 


LIMES, CEMENTS AND MORTARS. 95 


from the trowel it is of good quality, but if the mortar sticks to the 
trowel there is foo much sand in proportion to the lime. The color 
of the mortar depends much upon the kind and color of the sand 
used. | 

Many of the limes used in the Western States when slaked leave a 
residue of stones, lumps and gravel, so that instead of mixing the 
mortar in the same box in which the lime is slaked, a larger propor- 
tion of water is added, and the slaked lime and water (about as thick 
as cream) is run off through a fine sieve into another box, in which 
the mortar is mixed. Such lime does not make as good mortar as 
that which leaves no impurities, but it does very well for use in brick 
and stone work. 

The general custom in making lime mortar is to mix the sand with 
the lime as soon as the latter is slaked and letting it stand until 
required for use. Much stronger and better mortar would be 
obtained, however, if the sand were not mixed with the slaked lime 
until the mortar was needed. 

103. Sand.—The sand used in making mortar should be angular 
in form, of various sizes, and absolutely free from all dust, loam, 
clay or earthy matter, and also from large stones. It is generally 
necessary to pass the sand through a screen to insure the proper 
degree of fineness. For rough stonework a combination of coarse 
and fine sand makes the strongest mortar. For pressed: brickwork it 
is necessary to use very fine sand. The architect or superintendent 
should carefully inspect the sand furnished for the mortar, and if he 
has any doubts of its cleanliness, a handful put in a tumbler will at 
once settle the question, as the dirt will separate and rise to the top. 
Another simple method of testing sand is to squeeze some of the 
moist sand in the hand, and, if upon opening the hand the sand is 
found to retain its shape, it must contain loam or clay, but if it falls 
down loosely it may be considered as clean. Sand containing lcam 
or clay should be at once rejected and ordered from the premises. 
As a rule, it is better that the sand should be too coarse rather than 
too fine, as the coarse sand takes more lime and makes the strongest 
mortar. Some unscrupulous masons may attempt to use fine sandy 
loam in their mortar, as it takes the place of lime in making the mor- 
tar work easily ; but, of course, it correspondingly weakens the mor- 
tar, and its use should never be permitted. a" 

104. White and Colored Mortars.—White and colored mor- 
tars to be used in laying face brick should be made from “me putty 
and finely screened sand. After the slaked lime has stood for several 


96 BOILDING CONSTRUCTION. 


days the water evaporates and the lime thickens into a heavy paste, 
much like putty, and from which it takes its name of lime putty. By 
the time the putty is formed the lime is sure to be well slaked and will 
not then swell or “pop.’”’ Colored mortar is made by the addition of 
mineral colors to the white mortars. Colored mortar should zever be 
made with freshly slaked lime, but only with lime putty at least three 
days old. For Mortar Colors see Section 148. 


Common lime when slaked and evaporated io a paste may be kept 
for an indefinite time in that cond!tion without deterioration, if pro- 
tected from contact with the air so that it will not dry up. It is cus- 
tomary to keep the lime paste in casks or in the boxes in which it was 
slaked, covered over with sand, w se subsequently mixed with it in 
making the mortar. Clear lime putty may be kept for a long time in 
casks, for use in making colored mortar, only a little mortar being 
‘made up at a time. 


105. Setting.—Lime paste or mortar does not set like cement, 
but gradually absorbs carbonic acid from the air and becomes in time 
very hard; the process, however, requires from six months to several 
years, according to the thickness of the mortar and its exposure to 
the atmosphere. It permitted to dry too quickly it never attains its 
proper strength. If frozen, the process of setting is delayed and the 
mortar is much injured thereby. Alternate freezing and thawing 
will entirely destroy the strength of the mortar. Lime mortar will not 
harden uncer water, nor in continuously damp places, nor when 
excluded frou. ‘ontact with the air. 


06. Preserving.—Fresh burned lime will readily absorb mois- 
ture from a damp atmosphere, and will in time become slaked 
theréby losing all of its valuable qualities for making mortar. It 
is therefore important that great care should be taken to secure 
freshiy burned lime and to protect it from dampness until it can be 
used. If the lime is purchased in casks it should be kept in a dry 
shed or protected by canvas, and if it is bought in bulk it should be 
kept in a water-tight box built for the purpose. 


On no account should the superintendent permit of the use of air- 
slaked lime, as it is impossible to make good mortar of it. 


107. Durability of Lime Mortar.—Good lime mortar, when 
-_protected from moisture, has sufficient strength for all ordinary 
brickwork, except when heavily loaded, as in piers, and continues to 
grow harder and stronger every year. The writer has often seen 
instances in old walls where the lime mortar was as strong as the 


LIMES, CEMENTS AND MORTARS. 97 


bricks, and where the adhesion of the mortar to the bricks was greater 
than the cohesion of the particles of the bricks. 

A specimen of mortar, supposed to be the most ancient in exist- 
ence, obtained from a buried temple on the island of Cyprus, was 
found to be hard and firm, and upon analysis appeared to be made 
of a mixture of burnt lime, sharp sand and gravel, some of the frag- 
ments being about $ inch in diameter. The hme was almost com- 
pletely carbonized.* 

Lime mortar, however, attains its strength slowly, and where high 
buildings are built rapidly the mortar in the lower story does not 
have time to get sufficiently hard to sustain the weight of the upper 
stories, and for such work natural cement should be added to the 
lime mortar. 

HYDRAULIC LIME. 

108. Hydraulic limes are those containing, after burning, enough 
lime to develop, more or less, the slaking action, together with suffi- 
cient of such foreign constituents as combine chemically with lime 
and water, to confer an appreciable power of se¢#zng under water, and 
without access of air. 

The process of se¢temg is entirely different from that of drying, 
which is produced simply by the evaporation of the water. Setting 
is a chemical action which takes place between the water, lime and 
other constituents, causing the paste to harden even when under 
water. 

Hydraulic lime or cement should not be used after it has com- 
menced to set, as the setting will not take place a second time and 
the strength of the mortar will be lost. 

In the great majority of natural hydraulic limes commonly used 
for making mortar, the constituent which confers hydraulicity is cday, 
although silica also has the same effect. 

Hydraulic limes containing clay may be arranged in three classes, 
according to their amount of hydraulic energy: 

1. “ Feebly hydraulic—containing 10 to 20 per cent. of impurities. 
This slakes in a few minutes, with crackling, heat and emission of 
vapor. If made into a paste and immersed in water in small cakes, 
it will harden so as to resist crushing between the thumb and finger 
in from twelve to fifteen days. 

2. “ Ordinary hydraulic—containing 17 to 24 per cent. of impuri- 
ties. Slakes after an hour or two, with slight heat and fumes, with- 
out crackling. Sets under water in six or eight days. 





* William Wallace, Ph.D., F. R.S E., in London Chemical News, No. 281. 


98 BUILDINGLCONSLAUG LION. 


3. ‘ Eminently hydraulic—containing at least 20 per cent of imput. 
ities. Slakes very slowly and with great difficulty, with slight heat. 
Sets under water in twelve to twenty hours and becomes hard in twe 
to four days.” * 

Artificial hydraulic lime can be manufactured by mixing together, 
in proper proportions, thoroughly slaked common lime and unburnt 
clay, then burning and grinding in much the same manner as in the 
manufacture of Portland cement; but as the process of manufacture is 
nearly as expensive as for making Portland cement, it is more profit- 
able to make cement, on account of its superior hydraulic energy. 

No hydraulic lme is manufactured, artificially, in the United 
States, and but very few hydraulic limes are in use. 


A gray lime is obtained at Morrison and a few other locations in Colorado 
which hardens under water and makes very strong mortar. It is also sometimes 
used for making concrete. 


A very simple experiment will determine if a lime is hydraulic or 
not: Make a small cake of the hme paste, and after it has com- 
menced to stiffen in the air, place it in a dish of water s) that it will 
be entirely immersed. If it possesses hydraulic properties it will 
gradually harden, but if it is not hydraulic it will soften and dissolve. 

Hydraulic lime mortar is made in the same way as common lime 
mortar, care being taken to use sufficient paste to coat all grains of 
sand and to fill up the voids between them. 


109. Pozzuolanas is a name given to certain clayey earths con- 
taining 80 to go per cent. of clay, with a little hme and small quanti- 
ties of magnesia, potash, soda, oxide of iron, or manganese. 

When finely powdered in their raw state and added to lime mortar 
they confer hydraulic properties to a considerable degree. 

Natural Pozzuolana is a naturally-burnt earth of volcanic origin 
found at Pozzuoli, near Vesuvius, and in the caverns of St. Paul, 
near Rome. It is found in the form of powder, and when sifted is 
used all along the Mediterranean coast for making hydraulic mortars. 

Béton (similar to concrete) as prepared in that region is generally 
made of Pozzuolana, lime and aggregates in the following proportions: 


POGZUOLAI «sa 5 sino s ot emits tase go mr eo whe aS ee eee I2 parts. 
Baked Recs 25 acs -a 9 a) oles. Gwe swt enhe ale te ars eareg ane ene & + aeats, BEN On 
Good -qnitklime. <1 5 ada s.c genie afeuolnsereite's ¢ oc ete eeceane date eee Oe 
Small SOMES sais ccd cin e-slsle’'s-s-y'ackrgl e's ore emi Re erabebs eeratea he ennnene 73 Ohass 
Csromntl tela'g 7m. sere on pos eia a Seah eeel ene eee ees Penagas ececes int. 


* Ira O. Baker in ‘‘ Masonry Construction.”’ 


~ 


LIMES, CEMENTS AND MORTARS. 99 


Pozzuolana is not used in this country, but as the name is fre- 
quently found in books on masonry construction, it is well for the 
young architect to know what it is. 

Brick dust, mixed with common lime, produces a feebly hydraulic 
mortar, and adds materially to its strength. 


HYDRAULIC CEMENTS. 


Hydraulic cements are made by calcining limestones containing 
from 30 to 60 per cent. of clay. 

They do not slake or break up like lime, and their paste sets very 
quickly, either in air or water. 

They may be divided into two classes: 

1. Natural cements. 

2. Artificial cements. 


110. Natural Cements are made from a natural rock, of which 
the principal ingredients are carbonate of lime, carbonate of mag- 
nesia and clay. The stone, after being quarried, is broken into 
pieces of a suitable size and mixed with anthracite coal and burned 
in kilns specially constructed forthe purpose. Great care is required 
in selecting and preparing the stone for the kiln and in burning it to 
a consistent degree of calcination. 

After calcining the material is drawn out of the kilns and care- 
fully inspected. That which is properly burned is sent to the mill to 
be finely ground between ordinary millstones, and the underburned 
or over-calcined thrown away. 

Natural cements weigh about two-thirds as much as Portland 
cement, are very quick setting and have less ultimate strength. 
They attain their full strength, however, sooner than the Portland 
cements, and are sufficiently strong for all ordinary building opera- 
tions. 

They have been used in many of the largest building and engi- 
neering works in this country with perfectly satisfactory results, and 
their use is extending every year. 

They are sold at a less price than Portland cements, and in locali- 


_ ties where the cost of transportation is not excessive are almost exclu- 


sively used for cement mortar. 


111. Distribution of Natural Cements.—“ In no other coun- 
try in the world is there to be found cement rock formations which 
are at all to be compared with those so well distributed throughout 
the United States. . . . Here we have immense beds of cement 
rock absolutely free from any extraneous substances, perfectly pure 


100 BOLILDIN GICONSTROGLILION. 


and clean, with layer upon layer, extending for thousands of feet 
without appreciable variation in the proportion of the ingredients.” * 


Natural cements are manufactured in very many localities through- 
out this country, the cement being commonly known by the name of 
the place from which the stone is obtained, although, as there are 
often several manufactories in the same locality, there may be several 
brands of cement made from the same rock. The difference in the 
quality of such brands is generally due to the care exercised in 
their manufacture. 


The localities in which natural cements are made on an extensive 
scale are as follows: 


Rosendale, N. Y.—Natural cement was first made in this country in the town 
of Rosendale, Ulster County, N. Y., during the year 1823, for use in building the 
Delaware and Hudson Canal. Since then inexhaustible deposits have been found 
of the fine-grained natural stone out of which Rosendale cement is made, and 
there are several companies which manufacture cement from this rock, each hav- 
ing a special brand for their product. Owing to the length of time for which 
they have been used, and the special advantages enjoyed for transportation and 
nearness to the great building centres of the country, Rosendale cement is more 
widely known than any other of the natural cements. It is generally of a very 
good quality and well suited for building operations. 


Very good natural rock cements are also made at Buffalo, Akron and Howe’s 
Cave, N. Y. 


Louisville, Ky.—Louisville cement, made from natural rock quarried at this 
place, is probably the leading natural cement beyond the Alleghenies, the product 
being exceeded only by the production from the Rosendale district. There are 
several brands of this cement in the market, and they find their way as far west as 
the Rocky Mountains. 

At Utica, 7i/., a natural cement has been manufactured since 1838. This cement 
has always stood well in public favor, and is largely used throughout the West. 

At La Salle, 7il., a natural cement is manufactured from the same rock forma- 
tion as that running through Utica, III. 

The Wilwaukee Cement Co. manufactures a natural cement from rock obtained 
near Milwaukee, Wis., which is extensively used. 

Mankato, Minn.—A cement rock of the very best quality exists at this place, 
and the manufactured product has obtained a strong foothold in the markets of the 
Northwest. 

Cement, Ga.—The cement manufactured from stone quarried at this place 
‘‘probibly has no superior in this country. Used as an exterior plaster on a 
house in Charleston in 1852, the stucco still remains unimpaired, while the sand- 
stone lintels over the windows have long since been worn away.” 

Fort Scott, Kan.—A natural cement has been manufactured at this place since 
1867. The product resembles that of Cement, Ga. 





—_—-- 


* Uriah Cummings in the Brickbutlder. 


LIMES, CEMENTS AND MORTARS. IOI 


Natural cements are also manufactured at Siegfried’s Bridge, Lehigh Valley, 
Pa.; Balcony Falls, Va., and Cumberland, Md., and to a limited extent at severa) 
localities in the West. 

[An extended description of the natural cements manufactured in 
this country is given in a series of articles by Uriah Cummings in 
the Brickbuilder for 1895. | 

112. Analysis of Natural Cements.—The following table, 
giving the chemical constituents of the leading natural cements, will 
be found useful in comparing the products from different localities: 


TABLE VII.—TABLE OF ANALYSIS—NATURAL ROCK CEMENTS. 























: es < Fl 

ee ee tee Bess: : s | gé 

NUMBER. = = 5 = = i - 2 = 

= Dp 73 So) ia Mos 

a = 4 < E < ee 

2 e = fe) aa) 

= ey < 
Da datetr etsy yet? 24.30 2.61 6.20 39.45 6.16 5.30 15.23 
Drlenreietsee ates 34.66 & 0 I.00 30.24 18.00 6.16 4.84 
Suey tlemelae 27710 6233 Keay bi 36.08 20.38 5.27 7507 
Arnis sails Stare 26.40 6.28 1.00 45.22 g.00 4.24 7.86 
Ste ae ein a Site 25.28 7.85 T.43 44.65 9.50 4.25 7.04 
Omete arses wren 30.84 eS pares ip i 34.49 sy oy a 4.00 3204 
Det ee 27.30 7.14 | 1.80 35,98 | 18.00 | 6.86 2.98 
Oe eee oe 28 .38 Ee Tr 229 43.97 ae | 9.00 2.44 
APR Aen ae Satie g (le 8.64 2.00 azyT2 14.55 2.00 3.00 
LOGiae eG 2 ot nnd 24.34 8.56 2.08 61.62 0.40 2.00 0.80 
| A aaa Oe 22552 6.99 5.97 53.96 7370 2.00 
Pe Mic ats' © on ceecs 27.60 10.60 0.80 33.04 Rae TAZ 2.00 
Be otdtera eevee she 33.42 10.04 6.00 32°70 9.59 0.50 7.66 
bi Rae Ae ee 220 ke e235 3.35 48.18 15.00 3.66 
Roadie slate cosas 26.61 10.64 se50 Az s12 Ljer2 2.00 2.01 
TOdeee eis 25.15 8.00 | 3.28 49-53 13378 0.26 

REFERENCE: 


. Buffalo Hydraulic Cement, Buffalo, N. Y. 

. Utica Hydraulic Cement, Utica, IIl. 

Milwaukee Hydraulic Cement, Milwaukee, Wis. 

. Louisville Hydraulic Cement, ‘‘ Fern Leaf,’’ Louisville, Ky. 

. Louisville Hydraulic Cement, ‘‘ Hulme,” Louisville, Ky. 

. Rosendale Hydraulic Cement, ‘‘N. Y. & R.,’’ Rosendale, N. ¥. 
. Rosendale Hydraulic Cement, ‘‘ Hoffman,’”’ Rosendale, N. Y. 

. Cumbecland Hydraulic Cement, Cumberland, Md. 

. Akron Hydraulic Cement, ‘‘Cummings,’”’ Akron, N. Y. 

. California Hydraulic Cement, South Riverside, Cal. 


OI annp Wb 


se 
Op 


TI. Fort Scott Hydraulic Cement, ‘‘ Brockett,’’ Kansas City, Mo. 
12. Utiza Hydraulic Cement, La Salle, III. 
13. Shepherdstown Hydraulic Cement, Shepherdstown, Va. 


- 
SS 


- Howard Hydraulic Cement, Cement, Ga. 
. Mankato Hydraulic Cement, Mankato, Minn. 
. James River Hydraulic Cement, Balcony Falls, Ve. 


nw 


102 BUILDING CONSTRUCTION. 


113. Characteristics of Natural Cement.—Co/or.—The color 
of the natural cements used in this country vary with the locality in 
which they are found. Most of the cements mentioned in Section 
111 are brown in color, in light or dark shades. “In Rosendale 
cement a light color generally indicates an inferior, underburnt rock. 

“The weight of good Rosendale cement varies from 49 to 56 
pounds per cubic foot, or 60 to 70 pounds per bushel, according to 
its fineness and the density of packing. The harder-burned varieties 
are also heavier than those that are underburned. The weight per 
barrel of Ulster County Rosendale cement averages 300 pounds net ; 
Akron, Milwaukee, Utica and Louisville cements weigh 265 pounds 
per barrel net.” 

Testing Rosendale Cement.—The value of cements for 
making mortar varies greatly with their physical properties, and 
since one lot is liable to differ very much from another lot of the 
same brand, it is very necessary to be able to test the character of 
any particular cement. 

Brand.—Any particular brand of cement will generally average 
about the same strength and quality, and the architect should ascer- 
tain what brands of cement are giving the best satisfaction and spec- 
ify those brands. For ordinary building purposes it will only be nec- 
essary for the superintendent to examine the casks to see that they 
bear the brand specified and to see that the cement has not been 
injured by dampness. If the cement is found to have become hard 
or crusty, it has absorbed moisture and should not be used in making 
the mortar. 

If the superintendent has any doubts of the quality of the cement, 
let him take two handfuls of cement and mix with as little water as 
possible into two cakes; put one in water and leave the other in air. 
If the air cake dries of a light color without any particular well- 
defined cracks, and the water cake sets with a darker color and with- 
out cracks, the cement is probably good. If the cement cracks badly 
in setting, or if it becomes contorted (sometimes called blowing), it is 
positively poor and should be rejected. 

Another simple test of the sowndness of cement, which is the prop- 
erty of not expanding or contracting, or checking or cracking in set- 
ting, is to place some mortar in a glass tube (a swelled lamp chimney 
is excellent for this purpose) and pour water on top. If the tube 
breaks the cement is unfit for use in damp places. Any natural 
cements that give satisfactory results with these simple tests will 
answer for making mortar for any ordinary building construction. 


LIMES, CEMENTS AND MORTARS. | 103 


Where great strength is required in the mortar it is better to use 
Portland cement, but if for any reason Portland cement cannot be 
«btained, or its price prohibits its use, then the strength of the natural 
cement should be carefully tested, in the manner described in Sec- 
tions 117-123 for testing Portland cement. 


Clear Rosendale cement one week old in water should have a 
tensile strength per square inch of at least 60 pounds, and the best 
brands should average 100 pounds. 


Storing.—It is very essential that cements of all kinds should be 
stored in a dry place, where there is no danger of its absorbing mois- 
ture, until it can be used. A very little moisture will cause the 
cement to set, and any cement that has commenced to set should be 
rejected. 


114. Roman Cement is made by calcining nodules found in 
the London clay. The color of the calcined stone is generally a rich 
brown. 

Weight and Strergth—“ Good Roman cement should not weigh 
more than 75 pounds per bushel, and should set very quickly (within 
about fifteen minutes of being gauged into paste).’’ A heavier cement 
than this 1s likely to be overburnt or else injured by the absorption 
of carbonic acid from the air. 

Neat Roman cement seven days old in water should possess a ten- 
sile strength of from 50 to 80 pounds per square inch. 

Storing.—Roman cement is sold in a ground state and is put upin 
casks, which must be kept carefully closed and dry, otherwise the 
cement will absorb carbonic acid and become inert. 

Uses.—The strength of Roman cement diminishes rapidly when 
mixed with sand, and not more than 1 or 14 parts of sand to 1 of 
cement should be used in mixing the mortar. Roman cement mor- 
tar should be mixed in very small quantities and used at once, and 
on no account beaten up again after the setting has commenced. 


ARTIFICIAL CEMENTS. 


115. Portland Cement.—The most useful of artificial cements 
is that known as Portland cement. 

The first Portland cement was made by Joseph Aspdin, of Leeds, 
England, who obtained a patent on it, dated October 21, 1824. For 
making his cement he used powdered limestone and a certain quan- 
tity of clay, which he mixed together with water to a paste, then 
evaporated in pans. After evaporation the mixture was broken up 
into lumps, calcined at a high temperature and ground. 


104 BULEDING*CONSTROCTION. 


The name of Portland was given to the cement on account of the 
fact that when troweled to a smooth surface it resembled rubbed 
Portland stone, one of the chief building stones of England. 

“Portland cement requires a homogeneous mixture containing in 
proper proportions carbonate of lime, alumina (clay), silica and 
iron. . . . This mixture must be subjected to a heat sufficiently 
high to produce a vitrified, dense and heavy clinker, and afterward 
ground to a fine powder.” 

The proper proportions of the above ingredients are rarely found 
in a natural stone, so that it is necessary to obtain the lime and 
alumina from separate sources and mix them in the proper propor- 
tions artificially. 

At the present time the bulk of the English cement, and much of 
the German cement, is manufactured from chalk instead of the hard 
limestones. This chalk is mixed with clay in the proper proportions, 
before burning, in a large wash mill, and the slurry is then run off 
and dried, either by artificial means or sun evaporation. After dry- 
ing the mixture is burned at a fixed temperature into a scoriaceous 
mass, resembling pumice stone, to which the name of “clinker’’ is 
applied. This “clinker” being dried, ground to powder and passed 
through sieves, furnishes the finished product. 

The quality of the cement depends upon the quality of the raw 
materials, the proper proportion of the mixture, the degree to which 
it is burnt, the fineness to which it is ground, and constant and scien- 
tific supervision of all the details of manufacture. 

116. American Portland Cement.—The first American Port- 
land cement was manufactured by Mr. David O. Saylor in the year 
1874 at Coplay, Pa. Since that time several factories have been 
established in the United States, and in the year 1894 there were 
nineteen factories, which made about 700,000 barrels; this amount, 
however, being but 18 per cent. of what was imported. Most of the 
American Portland cement is manufactured in the neighborhood of 
Coplay, Pa., the largest factory being that of the Atlas Cement Co., 
where 1,800 barrels a day are now manufactured. ‘All the fac- 
tories located in this region make cement under the dry process from 
an argillaceous limestone. ‘There are several factories in New York 
State, along the Erie Canal, and in Ohio, where marl and clay or 
limestone and clay are used. Practically nine-tenths of the Port- 
land cement manufactured in this country is made in the States 
of Pennsylvania, New York and Ohio. Other States where small 
quantities are manufactured are Texas, Colorado, Dakota, Oregon, 
California and the Territory of Utah. There is plenty of raw material 





* ‘Ihe output of this Company in 1901 was over 3,000,000 barrels 


LIMES, CEMENTS AND MORTARS. 105 


suitable for making the highest grade of Portland cement, in almost 
every State in the Union.” * 

Several of the American Portland cements have been shown by 
thousands of carefully conducted tests to be equal in quality to any 
of the imported cements, and they have been used with perfectly sat- 
isfactory results in many of the largest engineering works in this 
country, as well as many of our largest buildings. The Mississippi 
jetties were built with American Portland cement, and they have suc- 
cessfully withstood the most severe test to which cement concrete can 
be subjected. 

Good Portland cement is slow-setting, as compared with the natural 
cements, but greatly surpasses them in ultimate strength. 

“The induration, or ‘setting,’ of Portland cement consists in the 
formation of a real mineral of a crystalline rock species, analogous to 
natural zeolites.”’ 

Owing to the greater expense in manufacturing Portland cement, 
its market price is nearly three times that of the Rosendale cemenis, 
but where great strength is required, as in brick or stone piers, or for 
concrete footings, Portland cement should always be preferred to any 
of the natural cements. 


117. Testing Portland Cement.—In all important engineer- 
ing works it is customary to test every fifth or tenth cask of cement 
for its soundness, fineness and strength. 

For use in building piers and footings for ordinary buildings, it 
will be sufficient if the superintendent sees that only brands bearing 
a good reputation are used and that none of the cement has com- 
menced to set or crust in the casks. Any such cement should be 
rejected. 

In places where great strength and durability is required of the 
mortar careful tests should be made of every lot of cement used, as 
one lot of cement may differ very much from another lot of the same 
brand. 


118. Color.—Some idea of the quality of the cement may be 
gained from its color, but it should be supplemented by further tests 
for strength and fineness, as a bad cement may be of good color. 
Good Portland cement, as received .from the manufacturers, should 
be of a gray or bluish gray color. 

A brown or earthy color indicates an excess of clay and shows that 
the cement is inferior—likely to shrink and disintegrate. A coarse, 


* William G. Hartranft, before the Master Builders’ Exchange of Philadelphia. 


i06 BUILDING CONSTRUCTION. 


bluish-gray powder is probably over-limed and likely to blow. An 
undue proportion of underburnt material is generally indicated by a 
yellowish shade. 


Weight.—The weight of Portland cement is sometimes specified 
as one of the requirements to be fulfilled, but as it is never constant, 
and cannot be precisely determined, it is of very little service in 
determining the value of a cement. 


The finer a cement is ground the more bulky it becomes, and, con. 
sequently, the less it weighs ; a light-burned cement also weighs less 
than one that is harder burned, so that light weight may indicate 
either a desirable fine grinding or an objectionable underburning. 


The weight of cement should be determined by sifting the cement 
into a measure with a fall of 3 feet and striking the top level with a 
straight-edge. The following values determined in this way give fair 
averages for ordinary cements: 


Portland, English and German........ 77 to gO lbs. per cubic foot. 
Portland, fine;cround Frenchoj isnt <> 69 ie 
Portland, Americanif. ssi. «ace e acne 95 ‘S se 
Romany siGa cae oom srovesiou cis eae et on eneres 54M e 
Rosendalets, .22 asc once oa noe see 49 to 56 ‘S a 


A bushel contains practically 1} cubic feet, so that the weight per 
bushel can be easily computed from the above table, if desired. 


119. Activity.—A mortar is said to have se¢ when it has attained 
such a degree of hardness that it cannot be altered without causinga 
fracture, z. ¢., when it has entirely lost its plasticity. Some cements 
set quickly, while others are comparatively slow. A quick-setting 
cement is especially valuable in constructions under water. 

Test of Activity—To test hydraulic activity mix cement with just 
enough clean water, at a temperature of from 65° to 70° F., to make 
a stiff paste and make one or two cakes or pats 2 or 3 inches in diam- 
eter and about 4} inch thick. As soon as the cakes are prepared, 
immerse in water at 65° F. and note the time required for them to 
set hard enough to bear a +4g-inch wire loaded to weigh + pound and 
4 pounds, respectively. “When the cement bears the light weight it 
is said to have begun to set ; when it bears the heavy weight it is said 
to have entirely set. Cements, however, will increase in hardness 
long after they can just bear the heavy wire. The activity of the 
cement is measured by the time which elapses between the time when 
the first weight is supported and that when the second is just borne.” 
An increase of temperature will cause the cement to set quicker 


LIMES, CEMENTS AND MORTARS. 107 


while cold retards it. As a rule Portland cements should support the 
heavy wire in from two to five hours. 

120. Soundness.—tTests for the soundness of Portland cement 
should be made in the same way as described in Section 113 for tests 
of Rosendale cement. The color of the cake dried in the air should 
be uniform bluish gray throughout, yellowish blotches indicating 
poor cement. The cake left in the water should be made with thin 
edges, and, if at the end of twenty-four hours it shows fine cracks 
around the edges, it is unsafe to use in damp places, but if there are 
no cracks it may be considered safe. This is a very simple test to 
make, and should be made in all cases where the cement is to be 
used under water. 

121. Fineness.—There is no doubt that properly burnt cement, 
when ground extremely fine, is, as compared with one coarsely 
ground, much stronger when used with sand, as the finer the parti- 
cles the better they can surround the cand and aggregates, thus more 
strongly cementing them together. The finely ground cement is 
also the safest to use. The hard-burnt cements, finely ground, make 
the strongest mortars. 

Measuring Fineness—“The degree of fineness of a cement is 
determined by measuring the per cent. which will not pass through 
sieves of a certain number of meshes per square inch.” A cement 
that will pass through a sieve of 2,500 meshes (No. 35 wire gauge) 
with only 5 to 10 per cent. residue is sufficiently fine for any build- 
ing construction. 

122. Strength.—The most important test of cement is that of 
its strength. This is generally made by testing the tensile strength 
of the cement either neat or mixed with sand. Although cement 
mortar is generally subject only to a compressive strain, its resistance 
to compression is so much greater than to tension that in most cases 
of the failure of mortar it is broken by tensile stress. 

Briquettes—The method of testing the tensile strength of cement 
or mortar is to form a cake or brick of the cement or mortar 
in a mould, and after a certain limit of time it is pulled apart and the 
force required for producing fracture carefully noted. Figs. 57 and 
58 show the shape of the briquette and the clamps for holding, as 
recommended by the Committee of the American Society of Civil 
Engineers. 

The Machine.—There are many machines for sale, made especially 
for testing the strength of cement. Fig. 59, from Baker’s “ Treatise 
on Masonry Construction,” represents a cement-testing machine that 


108 BOILDINGsCONSTRECLION, 


can be made by an ordinary mechanic at small expense. It is not as 
convenient nor quite as accurate as the more elaborate machines, but 
it is sufficiently accurate for all practical purposes. ‘The machine 





Fig. 57. Fig. 58. 


consists essentially of a counterpoised wooden lever, 1o feet long, 
working on a horizontal pin, between two broad uprights, 20 inches 
from one end. Along the top of the long arm runs a grooved wheel 
carrying a weight, W’. The distances from the fulcrum in feet and 





Fig. 59. 


inches are marked on the surface of the lever, and also the corre- 
sponding effect of the weight at each point. The clamp, C, for hold- 
ing the briquette is suspended from the short arm, 18 inches from 
the fulcrum. ‘The clamps are of wood and are fastened by clevis joints 
to the lever arm and bed plate respectively. The pin is iron and the 


IIMES, CEMENTS AND MORTARS. 109 


pin holes are reinforced by iron washers. When great stresses are 
required extra weights are hung on the end of the long arm. Pres- 
sures of 3,000 pounds have been developed with this machine.” 

In applying the load on the briquette it 1s recommended that it 
start at o and be increased regularly at the rate of 400 pounds per 
minute for neat Portland cement, and 200 pounds per minute for 
natural cements and mortar. 

A rough test may be made by suspending the clamps from a beam 
or trestle and hanging a bucket or box from the lower clamp, into 
which sand may be run until the briquette breaks, and the weight 
then weighed. 

123. Mixing the Mortar—Cements should be tested, both neat 
and mixed with sand. Briquettes made entirely of cement are more 
convenient for testing, as they may be tested sooner, and there can 
be less variation in the mixture. But in building, cement is rarely 
used without an admixture of sand, and the most valuable compara- 
tive test of different brands submitted would be to make the bri- 
-quettes of cement and sand such as is to be used in the mortar, as 
while one cement might give a greater strength when used without 
sand, when mixed with the sand it might show a less result than 
another brand, owing to the comparative fineness of the two. 

Practically the benefit to be obtained in testing the strength of 
cements for building purposes will be to determine which of the 
brands that are available are the most desirable, considering both the 
cost and the strength, although where a certain strength is specified 
the cement submitted by the contractor should be tested to see if it 
meets the requirements of the specifications. 

In comparing different brands of cement great care should be used 
to see that the same kind and quality of sand is used in each case, as 
difference in the sand might cause as much difference in the results 
as there would be between the cements. It is recommended that an 
average of at least five briquettes of each brand of cement be taken 
as the strength of the cement. 

The manner of making the briquettes should be as follows: Ona 
thick glass plate lay sheets of blotting paper soaked in water, and on 
top of each sheet place a mould wetted with water. Before mixing 
the mortar an experimental batch should be made to determine the 
exact amount of water required to mix the cement to the proper con- 
sistency. If the cement is mixed with sand, both the cement and 
the dry sand should be carefully wezghed to get the desired propor- 
tions, 1 to rt or 1 to 3, as desired, and the sand and cement thoroughly 


110 BUILDING CONSIROGIION, 


mixed dry in a tight box. All the water required for mixing 
should be added at once, and the whole mass thoroughly and rapidly 
mixed for five minutes. “With the mortar so obtained the moulds 
should be at once filled with one filling, so high as to be rounded on 
top, the mortar being well pressed in. The projecting mortar should 
then be pounded with a trowel, first gently and from the side, then 
harder into the moulds, until the mortar grows elastic and water 
flushes to the surface. A pounding of at least one minute is essen- 
tial. The mass projecting over the mould should now be cut off with 
a knife and the surface smoothed.” The briquettes should be removed 
from the moulds as soon as they are hard enough to stand it without 
breaking, and should be placed in a box lined with zinc and provided 
with a cover. The briquettes should remain in the box twenty-four 
hours, after which they should be placed under water, to remain until 
tested. They should be constantly covered with water until tested, 
which should be done as soon as they are taken from the water. 

Age of Briquette for Testing —Half of the briquettes are generally 
tested at the end of seven days, and the remainder at the end of 
twenty-eight days. Ifit isimpracticable to wait twenty-zight days they 
may be tested at the end of one and seven days respectively, and the 
ultimate strength of the cement judged by the increase in strength 
between the two dates. When sand is used in making the briquettes 
it is desirable to wait until the briquettes are twenty-eight days old. 

124. Data on Strength.—Table VIII., from the report of the Com- 
mittee of the American Society of Civil Engineers on Uniform 
Tests of Cements, sives the results of the average minimum and max- 
imum tensile strength per square inch which some good cements have 
attained when tested under the conditions above described. 


TABLE VIII.--TENSILE STRENGTH OF CEMENT MORTARS. 





AV. TENSILE STRENGTH 


AGE OF MORTAR WHEN TESTED. Pie Ea ete LL 





PORTLAND. | ROSENDALE, 





Clear cenzent. Min. | Max. | Min.| Max. 
1 day—r hour, or until set, in air, the remainder of the time in water.| 100] 140 49 80 
1 week—r day in air, remainder of the tine In Water ya. see <4 seep “250 | 550 60 100 
4 weeks—1 day in air, remainder of the time in water........+.0....- 350) 1 700 IselLoos|seTso 
t year—r day in air, remainder of the time in water . 4... ess.0se. os- 45@ | 800] 300] 4oo 
I part cement to 1 part sand 
x week—1 day in air, remainder of the time IN WAtEL....ceeseoseces Py pete eS 30 
4 weeks—1 day in air, remainder of the time in water........+...+-.- sfeas. |ycsts 50 80 
I year—1 day in air, remainder of the time in WALEED ci asie's clea ls cieieinstre Bae | irae, 200 | 300 
I part cement to 3 parts sand. 
x week—1 day in air, remainder of the time in water 24.4. 0e-ce=nes : 80 | 125 
4 weeks—1 day in air, remainder of the time in water .cccsscsdccseed 100 | 200 


I year—1 day in air, remainder of the timean water. ae nsaeeomeee 200 | 350 





LIMES, CEMENTS AND MORTARS. Itt 


The quantities in the “ Min.” columns give the average strength 
of the weaker brands of Portland and Rosendale cements, and those 
in the “ Max.” columns the average strength for the stronger brands. 
By comparing his results with the values in this table, the architect 
or superintendent can judge whether his cement is satisfactory or not. 


Limit to Increase of Strength with Age-—F¥rom a series of experi- 
ments made by Mr. Grant in England with a heavy cement, he was 
led to the conclusion that it attained its maximum strength after con- 
stant immersion for two years, and that there is no reason to fear that 
a good cement ever deteriorates. With a light cement the maximum 
strength would probably be attained much sooner. 


125. Specifications for Cement.—In works where it is 
important to have a first-class cement the specifications should read 
about as follows, and all brands submitted should be carefully tested, 
and those which do not meet the requirements should be rejected: 


Spectfication.—The whole of the cement shall be Portland cement 
of the very best quality, weighing not less than 110 pounds to the 
striked bushel, ground so fine that not over 1o per cent. will be 
rejected by a sieve of 2,500 meshes per square inch (No. 35 wire) 
and capable of maintaining a breaking weight of 350 pounds per 
square inch after hardening one day in air and six days in water, 
and shall show no cracks or blotches when left under water twenty- 
four hours. 

Any cement that will fulfill these requirements should be good 
enough for any building construction or foundation. 


126. Lafarge Cement.—This is a patented preparation of cement 
similar in character to Portland cement, made from a limestone of 
hydraulic properties. It is hydraulic in character, but, unlike Port- 
land or Rosendale cement, does not stain marble, limestone and other 
porous stones when used in setting them, and therefore is especially 
desirable for setting such stones. 

For setting large stones mix 1 part by volume of lime paste to 4 
parts of the cement, to retard the setting of the cement until the 
stones are well bedded. 


CEMENT MORTARS. 


127. Use.—Cement mortar should be used for all mason work 
below grade, or where situated in damp places, also for heavily loaded 
piers and in arches of large span. It should be used for setting cop- 
ing stones, and wherever the mason work is especially exposed to tha 
weather. 


112 BULEDING CONT RUCL/ ON, 


For construction under water, and in heavy stone piers or arches, 
and for concrete, Portland cement should be used; elsewhere natural 
or Rosendale cement mortar will answer. 

128. Mixing the Mortar.—For use in ordinary masonry cement 
mortar should be mixed about as follows: Spread about half the sand 
required for mixing evenl, over the bed of the mortar box (which 
should be water tight), and then spread the dry cement evenly over 
the sand and spread the remaining sand on top. Thoroughly mix 
the dry sand and cement with a hoe or shovel, as this is a very essen- 
tial part of the process. The dry mixture should be shoveled to one 
end of the box and water poured into the otherend. ‘‘Cements vary 
greatly in their capacity for water, freshiy-ground cements requiring 
more than those that have become stale. An excess of water is, 
however, better than a deficiency, particularly when a very energetic 
cement is used, as the capacity of this substance for absorbing water 
is great.” The sand and cement should then be drawn down with a 
hoe in small quantities and mixed with the water until enough has 
been added to make a good s#zf# mortar, care being taken not to get 
it too thin. This should be vigorously worked with a hoe for five 
minutes to get a thorough mixture. The mortar should leave the hoe 
clean when drawn out of it, very little sticking to the steel. But a 
very small quantity of cement mortar should be mixed at a time, par- 
ticularly that made of Rosendale cements, as the cement soon com- 
mences to set, after which it should not be used. Asa rule natural 
cement mortars should not be used after they have been mixed two 
hours, and Portland cement mortars after four hours (for best work 
not over one hour). 

The sand and cement should not be mixed so as to stand over 
night, as the moisture in the sand will destroy the setting qualities 
of the cement. 

Should be Kept Moist.—“ Hydraulic cements set better and attain 
a greater strength under water than in the open air; in the latter, 
owing to the evaporation of the water, the mortar is liable to dry 
instead of setting. This difference is very marked in hot, dry 
weather. If cement mortar is to be exposed to the air it should be 
shielded from the direct rays of the sun and kept moist.” 

129. Proportion of Sand.—“ A paste of good hydraulic cement 
hardens simultaneously and uniformly throughout the mass, and its 
strength is impaired by any addition of sand.” As mortar is never 
used by itself, however, but as a binding material for brick and stone, 
and there can obviously be no advantage in making the strength of 


LIMES, CEMENTS AND MORTARS. 113 


the mortar joints greater than that of the bricks or stones they unite, 
sand is always added to the cement in making mortar. As cement is 
much more expensive than sand, the larger the proportion of sand in 
the mortar the less will be its cost. The proportion of sand should 
vary according to the kind of cement and the kind of work for which 
the mortar is to be used. For natural cements the proportion of sand 
to cement by measurement should not exceed 3 to 1, and for piers and 
first-class work 2 to 1 should be used. Portland cement mortar may 
contain 4 parts of sand to 1 of cement for ordinary mortar, and 3 to 
1. for first-class mortar. For work under water not more than 2 parts 
of sand to 1 of cement should be used. When cheaper mortars than 
these are desired it will be better to add lime to the mortar instead 
of more sand. ’ 


Plastering mortar, for stucco work or waterproofing, should be 
made of 1 part cement and 1 part sand. For lining cisterns 2 parts 
of natural cement or 1 of Portland cement should be used. 

The following table shows the comparative strength of English 


Portland cement mortar, with different proportions vf sand and at 
different ages: 








PROPORTION OF CLEAN PIT SAND TO I CEMENT. 
AGE AND TIME 
IMMERSED, 











Ser TeLORLs 2tol. By KO) tic AMOnl ea Sp tOe Le 
Gresweek J ecw cen 'ns. 445.0 152.0 64.5 44.5 2D Op lere acs 
Ome month... 6260s 5 679.9 3260.5 166.5 gI.5 Ria 49.0 
pennee months... 3.2. < S770 549.6 451.9 305.3 153.0 123.5 
Siler om tis, soit ae a's oh 978.7 639.2 497.9 304.0 275.6 218.8 
ON Te: MOTE TS shim 6 ee.a) oe 995.9 718.7 594.4 OR NOe wea ster: Rehr 
Twelve months........ 1 Oar 795-9 607.5 424.4 317.6 215.6 














—— 


P. 177, ‘‘ Notes on Building Construction,”’ Part III. 





The values in the table represent the breaking strength in pounds 
on a sectional area of 21 square inches. The superintendent should 
see that the cement and sand for each batch of mortar are carefully 
- measured to get the right proportions. 


130. Portland and Rosendale Cement, Mixed.— Whenever 
a quick-setting cement is desired, which shall attain a greater 
strength than the natural cements, a mixture of Portland and natural 
cement may be used. “Such mortar sets about as quickly as if made 
with natural cement alone, and acquires great subsequent strength, 
due to the Portland cement contained in it. The strength of the 


114 BUILDING CONSTAEOGLION: 


mixed mortar is almost exactly a mean between that of the two mor. 
tars separate.” 


131. Lime with Cement.—An economical and strong mortar 
for use in dry places may be made by mixing Rosendale cemert with 
lime mortar, in the proportion of 1 part of cement to 4 parts of lime 
mortar. ‘The lime mortar should be well worked and the lime thor- 
oughly slaked before the cement ts added, and only a small quantity of 
the cement and lime mortar should be made up atatime. Such a 
mortar has a strength which is about a mean between that of lime 
mortar and Rosendale cement mortar, and which is amply sufficient 
for ordinary brickwork. Portland cement, mixed with lime mortar 
in the above proportion, gives no better results than good Rosendale 
cement. It is better to use a small proportion of lime with cement 
mortar than to use too large a proportion of sand, as the latter makes 
the mortar porous and liable to disintegrate rapidly. In England a 
mixture of Portland cement and lime mortar appears to be much 
used. Lime should not be added to cement mortar when it is to be 
used in wet places. 


132. Grout is a very thin liquid mortar sometimes poured over 
courses of masonry or brickwork in order that it may penetrate into 
empty joints left in consequence of bad workmanship. It is also 
sometimes necessary to use it in deep and narrow joints between 
large stones. Its use is not generally recommended by writers on 
mortars, and the writer believes that it should not be used in stone- 
work where it can be avoided. For brickwork, however, the author 
feels convinced that walls grouted with a moderately thin mortar 
every course makes a solid job. If the bricks are well wet before lay- 
ing, and every joint slushed full of stiff mortar, it is impossible to get 
anything stronger ; but in most localities it is difficult to get such work 
without keeping an inspector constantly on the ground, and when the 
walls are grouted the joints are sure to be filled. In his own prac- 
tice the author always specifies grouting for all brick footings and 
foundation walls. Many of the largest buildings in New York City 
have grouted walls. 


133. Data for Estimates—The following memoranda, made up 
from data given by Prof. Baker, will be found useful in estimating 
the amounts of materials required in making any given quantity of 
mortar: 


Lime Mortar.—A barrel ‘of lime weighs about 230 pounds; a 
bushel of lime, 75 pounds One barrel (or three bushels) of lime and 


LIMES, CEMENTS AND MORTARS. 115 


1 yard of sand will make 1 yard of 1 to 3 lime mortar, and will lay 
about 80 cubic feet of rough brickwork or common rubble. 

Cement Mortar.—x.8 barrels, or 540 pounds, of natural cement 
and .94 cubic yards of sand will make 1 cubic yard of 1 to 3 mortar; 
two barrels, or 675 pounds, of Portland cement and .g4 cubic yard 
of sand will also make 1 cubic yard of 1 to 3 mortar; 1.7 barrels, or 
525 pounds, of Portland cement and .98 cubic yard of sand will make 
1 cubic yard of 1 to 4 mortar; 1 cubic yard of mortar will lay from 
67 to 80 cubic feet of rough rubble or brickwork, from go to 108 
cubic feet of brickwork with 2 to }-inch joints, and from 324 to 378 
cubic feet of stone ashlar. 

A cubic foot of common brickwork contains about eighteen bricks. 

134. Strength of Mortar.—The exact strength of mortar to resist 
compression 1s not of very great importance, as it seldom, if ever, 
fails in this way. The tensile and adhesive strength of mortar is 
more important, particularly the latter, as whenever a building has 
fallen from using poor mortar it has generally been on account of the 
failure of the mortar to adhere to the bricks or stones. Whatever 
kind of mortar is used, it should be made rich and well worked, as 
the saving by using more sand is but a small percentage at most, and 
it is never safe for an architect to allow poor mortar to be used in his 
buildings. 

The safe crushing strength of Portland, Rosendale and lime mor- 
tars used in $-inch joints should equal the following values in tons 
per square foot: 

Portland cement mortar, I to 3, 3 months, 40 tons; I year, 65 tons, 
Rosendale ‘‘ ae I to 3, 3 months, 13 tons; I year, 26 tons. 
Lime mortar, I to 3, 3 months, 8.6 tons; I year, 15 tons. 

From these values we see that for granite piers, heavily loaded, 
only Portland cement mortar should be used. For all piers loaded 
with over 10 tons per square foot, and not exceeding 20 tons, Rosen- 
dale cement mortar should be used. Lime mortar should never be 
used for piers that are to receive their full load within six months. 

135. “ Zhe adhesion of mortars to brick or stone varies greatly 
with the different varieties of these materials, and particularly with 
their porosity. The adhesion varies also with the quality of the 
cement, the character, grain and quantity of the sand, the amount of 
water used in tempering, the amount of moisture in the stone or 
brick, and the age of the mortar.” 

Mortar adheres to both stone and brick better when they are wet 
(unless the temperature is below the freezing point), and the architect 


116 BOUTLDING COMER OCLION. 


should always insist on having the bricks well wet down with a hose 
before laying. A dry brick absorbs the moisture from the mortar so 
that it cannot harden properly and destroys its adhesive properties. 
The wetting of the brick is fully of as much importance as the quality 
of the mortar in brickwork. The adhesive strength of the cements 
and lime are as a rule in proportion to their tensile strength. There- 
fore where great adhesive strength is desired to prevent sliding, asin 
arches, etc., either Portland or Rosendale cement should be used, 
according to the importance of the work and stress to be resisted. 
Some years ago the walls of a brick building in New York City were 
pushed outward by barrels of flour piled against the walls, so that the 
walls suddenly fell into the street. An examination of the mortar 
showed that it was of poor quality, with little adhesion to the bricks. 
Had good mortar been used and the brick well wet, the failure (it 
should not be called an accident) would not have occurred. The 
adhesive and tensile strength of mortar is also of great importance in 
resisting wind pressure and vibration. 

136. Mortar Impervious to Water.—A frequent case of the failure 
of masonry is the disintegration of the mortar in the outside of the 
joints, although this does not take place to such an extent in build- 
ings as in engineering works. “ Ordinary mortar—either lime or 
cement—absorbs water freely, common lime mortar, absorbing from 
50 to 60 per cent. of its own weight, and the best Portland cement 
mortar from 10 to 20 per cent., and consequently they disintegrate 
under the action of the frost. Mortar may be made practically non- 
absorbent by the addition of alum and potash soap. One per cent., 
by weight, of powdered alum is added to the dry cement and sand 
and thoroughly mixed, and about 1 per cent. of any potash soap 
(ordinary soft soap made from wood ashes is very good) is dissolved 
in the water used in making the mortar. The alum and soap com- 
bine and form compounds which are insoluble in water. These com- 
pounds are not acted upon by the carbonic acid of the air, and add 
considerable to the early strength of the mortar and somewhat to its 
ultimate strength.’* The alum and soap are comparatively cheap 
and can be easily used. 

The mixture could be advantageously used in plastering basement 
walls and on the outside of buildings, and would add greatly to the 
durability of mortar used for pointing. 

137. Plaster of Parts in Mortar.—Plaster of Paris, which is su!- 
phate of lime, when added to either lime or cement mortar in 





* ‘* Treatise on Masonry Construction,’ Baker. 


LIMES, CEMENTS AND MORTARS. It7 


quantities not exceeding 5 per cent., accelerates the setting and also 
increases the early and the ultimate strength of mortar. Lime mor- 
tar to which plaster of Paris has been added is called gauged mortar. 
— Selenetic cement, an artificial cement much used in England, is made 
by combining plaster of Paris and hydraulic lime, in the proportion 
of three pints of the plaster to a bushel of unslaked lime. The addi- 
tion of the plaster of Paris to lime appears to increase the strength of 
the mortar from two to three times. 


138. Sugar in Mortar.—Sugar has been employed for centuries in 
India as an ingredient of common lime mortar, and adds greatly to 
the strength of the mortar. 

An addition of sugar or syrup equal to one-tenth of the weight of 
the unslaked lime, to lime mortar, adds 50 per cent. to the strength 
of the mortar and will cause the mortar to set more quickly. The 
addition of sugar to lime mortar is especially beneficial when used in 
very thick walls, as the lime mortar thus placed never becomes fully 
saturated with carbonic acid. 

Sugar added to Rosendale and Portland cement mortars in the pro- 
portion of 4 to 4+ per cent. in weight of the cement, increases the 
strength of the mortars about 25 per cent. 

As the combination of sugar and lime is soluble in water, sugar 
should not be added to mortar that is to be used under water. 


139. Preezing of Mortar.—Freezing does not appear to injure 
lime mortar 2f the mortar remains frozen until tt has fully set. Alter- 
nate freezing and thawing materially damages the strength and adhe- 
sion of lime mortar, and as this is generally what happens when mor- 
tar is laid in freezing weather, it is much the safest rule for the archi- 
tect to specify and see that no masonry shall be iaid with lime mortar 
in freezing weather. ‘“ Mortar composed of 1 part Portland cement 
and 3 parts of sand is entirely uninjured by freezing and thawing. 
mortar made of cements of the Rosendale type, in any proportion, is 
entirely ruined by freezing and thawing.” * 

Salt in Mortar.—When it is desired to use natural cement mortar 
in freezing weather the mortar should be mixed with water to which — 
salt has been added in the proportion of one pound of salt to eighteen 
gallons of water, when the temperature is at 32° F., and for each 
degree of temperature below 32° add three additional ounces of salt. 
Mortar mixed with such a solution does not freeze in ordinary winter 
weather, and hence is not injured by frost. 





* Trans. Am. Soc. of C. E., Vol. XVI., pp. 79-84. 


118 BUILDING CONSTRUCTION. 


When masonry must be laid in freezing weather the bricks or stones 
should be warmed sufficiently to thaw off any ice upon their surface or 
in the pores of the bricks before being laid. 


Builders sometimes advocate the addition of lime to Rosendale 
cement mortar in cold weather to warm it. The heating effect of the 
lime, however, would not be appreciable, as heat is generated in lime 
only when it slakes. If cement of the Rosendale type must be used 
in freezing weather, the only safe way of using it is by the addition 
of salt, as described above, otherwise the mortar will be completely 
ruined by freezing. 

Change of Volume in Setting.—Cement mortars diminish 
slightly in volume in setting in air and expand when under water, 
but the expansion and contraction is not sufficient to injuriously 
affect building construction. 


CONCRETE. 


140. There is probably no material that is so enduring, or better 
adapted for foundations (and also walls, vaults, etc.), than cement 
concrete, and perhaps none that is so much “skimped.” 

Concrete may be defined as an artificial rock, made by uniting 
sand, broken stone, gravel, fragments of brick, pottery, etc., by means 
of lime or cement. 

Concrete made with lime, however, is not suitable for damp situa- 
tions, and even when used for walls above ground it is much better 
to use either a “Portland” or “natural”? cement for the uniting 
material. 

Concrete made with good Portland cement, in proper proportions, 
becomes so hard and strong that when pieces of the concrete are 
broken the line of fracture will often be found to pass through the 
particles of stone, showing that the adhesion of the cement to the 
stone is greater than the strength of the stone. . 

For the aggregates no material is better than clean, freshly broken 
stone, in size about as large asa hen’s egg. Granite probably makes 
the best aggregates, but other hard stones will answer for any ordi- 
nary concrete. Soft sandstones or “freestones.””’ are not desirable. 
Pieces of hard brick or dense terra cotta also make good aggregates. 

Whatever material is used it is essential that it be free from dirt 
and that the particles be clean. 

Good clean, coarse gravel is also extensively used for the mass of 
the concrete, and some architects and builders prefer it to broken 
stone, but as all gravel has more or less rounded and smooth surfaces, 


LIMES, CEMENTS AND MORTARS. II9 


it would seem as though the cement must adhere more firmly to 
angular and broken surfaces. 

A certain proportion of clean, coarse sand is also required to fill 
the voids between the particles of stone or gravel. 

The method of making and using concrete is very simple, but 
owing to the fact that it is impossible to tell from an examination of 
the product the amount of cement that has been used, and the great 
temptation to the contractor to use as little cement as possible, not 
more than one-half or two-thirds of the amount of cement specified 
is generally used (unless an inspector is kept on the work), and the 
mixing of the materials is also often very imperfectly done. 

141. Measuring the Materials.—The only proper way to 
make concrete is:by carefully measuring the proportions of cement, 
sand, broken stone, etc. This may readily be done by using the 
common mason’s wheelbarrow for a unit of measure and mixing 
together the specified number of barrows of each material. 

For ordinary building operations, where the concrete is mixed by 
hand, as much concrete as may be made by two barrows of cement 
is all that can be worked at one time to advantage. The ordinary 
barrel of cement will just about fill two barrows, so that one barrel of 
cement may be considered as equal to two barrows, or parts. If the 
proportion is specified in this way, however, the inspector should 
have a barrel emptied into two barrows, and then permit the barrows 
to be filled with the sand and gravel only to the extent that they are 
filled by the cement. 

142. Manner of Mixing.—The most satisfactory method of 
mixing concrete by hand is to first prepare a tight floor of plank, or, 
better still, of sheet iron with the edges turned up about 2 inches, for 
mixing the materials on. 

Upon this platform should first be spread the sand, and upon this 
the cement. The two should then be thoroughly and immediately 
mixed by means of shovels or hoes, and the broken stone or aggre- 
gates then dumped on top and the whole worked over dry with 
shovels, and then worked over again while water is added from a 
sprinkler on the end of a hose. Only as much water should be added 
as is necessary to cause the cement to completely coat and cause to 
adhere all the particles of the aggregates. Too much water will 
lessen the strength of the concrete. 

The water used should be clean and at about the temperature of 65°. 

There are many machines for mixing mortar, which, for large 
quantities of concrete, effect a saving in the cost of mixing, and 


120 BUILDING CONSTROGLION. 


probably do the work more thoroughly and evenly. As soon as the 
concrete is mixed it should be wheeled to the trenches in barrows 
and dumped. 

Instead of first mixing the cement and sand, very good results may 
be obtained, with perhaps a little less labor, by depositing the broken 
stone on the sand after it is spread over the platform, and then the 
cement on top of the stone, and working the whole over dry with 
shovels. The first method, however, is to be preferred where an 
extra quality of concrete is desired. 

143. Proportions.—The best proportion of cement, sand and 
aggregates will depend upon the kind and quality of the cement used 
and the character of the work. 

The proportion of sand to aggregates should be such that the sand 
will just fill the voids in the aggregates. This will, of course, vary 
with the size of the aggregates and the coarseness of the sand. For 
stone broken to go through a 23-inch ring, about one-half as much 
sand as stone is required, on an average, to ill the voids. After one 
batch of concrete has been deposited and rammed the inspector can 
generally tellsby the appearance whether too much or too little sand 
has been used. 

_ Natural Cement Concrete-—For concrete foundations under build- 
ings of moderate height, and for foundations for cement pavements, 
natural cements make as strong concrete as is required. 

For the best brands of natural cements 1 part cement, 2 parts sand 
and 4 parts gravel or broken stone should be used. 

[This proportion was used in the foundations of the Brooklyn 
Bridge. | 

Portland Cement Concrete.—¥or concrete to be used under heavy 
buildings and under water Portland cement should be used. 

For the best brands of cement 2 parts of cement to 5 of sand and 
9 of broken stone will answer for almost any building construction. 
Much larger proportions of sand and aggregates than these are often 
used, but the author would not recommend a greater proportion than 
the above unless the quality of the cement is constantly tested and 
only the best used, and the concrete mixed under rigid inspection. 

144. Examples of Portland Cement Concrete—Foundations of 
Mutual Life Insurance Company’s Building, New York: 1 part 
cement, 3 parts sand, 5 parts broken stone. 

Foundation of U. S. Naval Observatory: 1 part cement, 2} sand, 
3 gravel, 5 broken stone. [1 barrel of cement, 380 pounds, made 
1.18 yards of concrete. | 


LIMES, CEMENTS AND MORTARS. 2 


Foundations of Cathedral of St. John the Divine, New York: 13,000 
cubic yards of concrete have been used in the foundation of the tower 
and choir, the average depth being 15 feet. Proportions: 1 part Port- 
land cement, 2 parts sand, 3 parts quartz gravel, 14 to 2 inches in 
diameter. 

Filling of caissons, Johnston Building (fifteen stories) New York : 
1 part Portland cement, 3 parts sand, 7 parts stone, finished on top 
for brickwork with 1 part cement and 3 parts gravel. 

Manhattan Life Insurance Building, New York, filling of caissons: 
1 part Alsen Portland cement, 2 parts sand, 4 parts broken stone. 

The proportion of cement is sometimes specified as “one barrel 
of cement to a yard of concrete,” but as it is very inconvenient to 
measure the concrete by the yard such a specification is not to be 
recommended. ; 

145. Depositing.—As soon as a batch of concrete is mixed it 
should be wheeled to the trenches and deposited in layers from 6 to 
Io inches in thickness. Where the total thickness of concrete does 
not exceed 18 inches the layers should not be more than 6 inches 
thick. The concrete should not be dumped from a greater height 
than 4 feet above the bottom of the trench. If dumped from a greater 
height the heavy particles are apt to separate from the lighter ones. 

As soon as a square yard of concrete has been deposited it should 
be tamped with a wooden rammer weighing about 20 pounds. ‘The 
tamping should be sufficient to just flush the water to the surface. 
The concrete should not be permitted to dry too quickly, and if 
twenty-four hours elapse between depositing the successive layers the 
top of each layer should be sprinkled before the next is deposited. 

146. Strength of Concrete.—The writer is not acquainted with 
any reliable tests on the compressive strength of concrete, but it is 
generally assumed that the strength of thoroughly mixed concrete is 
equal to that of mortar made of the same proportions of sand and 
cement. The crushing strength of 6-inch cubes of 1 to 2 Portland 
cement mortar was found by tests made at the Watertown Arsenal to 
average about 500 pounds per square inch, or 36 tons per square foot. 
For the working strength of concrete the author recommends the fol- 
lowing values, the larger values being for work done under strict 
inspection with the best of cement : 

Portland cement concrete, 1 to 8, 8 to 20 tons per square foot; 
natural cement concrete, 1 to 6, 5 to 10 tons per square foot. 

The estimated weight to be imposed on the concrete footings of 
the Cathedral of St. John the Divine is 10 tons per square foot. 


122 BUILDING CONSTROEGTLION: 


147. Data for Estimating.—There seem to be few records of 
careful measurements of the amount of materials required to make a 
cubic yard of concrete, but the following data is believed to be rea- 
sonably accurate : 

Used in the proportion of 1 part cement, 3 of sand and 5 of broken 
stone, in sizes not exceeding 2x1$x3 inches, one barrel of cement 
will make from 22 to 26 cubic feet of concrete, the average being 
about 23 cubic feet. 

In putting in the foundations of the Cathedral of St. John the 
Divine, New York, it required 17,000 barrels of Portland cement to 
make 11,000 yards, or about one and one-half barrels to the yard. 
The proportions were 1, 2 and 3. 

Concrete made of 1 part cement, 24 of sand, 3 of gravel and 5 of 
broken stone gave 1.18 yards of concrete to a barrel of cement. 

The ordinary cement barrel contains about 3? cubic feet. 

At $2 a day for labor, the cost of mixing and depositing concrete 
should not exceed $1 a cubic yard. The cost per yard of Portland 
cement concrete will generally vary from $6 to $8, according to the 
cost of the cement, labor and aggregates. 


MORTAR COLORS AND STAINS. 


148. The use of artificial coloring in mortars has been in vogue, 
more or less, for two thousand years, but the general use of colored 
mortars dates from a comparatively recent period. 

The object aimed at in using colored mortars is either to get the 
effect of a mass of color, by concealing the joints, or else, by using 
a contrasting color, to emphasize the joints. Rougher bricks may 
also be used with nearly as good effect by using a mortar of the same 
color as the bricks. Chipped or uneven edges do not show as plainly 
with mortar of the same color as the bricks as they do when laid with 
white mortar. 

Objections to Mortar Colors.—The objection is sometimes made to 
the use of colored mortars that they are not as strong as white mor- 
tars and that the color is very apt to fade. 

These objections undoubtedly have much truth in them when 
cheap colors are used and the mortar is not properly mixed, but it is 
very doubtful if the better grades of mortar colors now on the market 
affect the strength of the mortar to any appreciable extent, and when 
properly mixed with lime putty they seldom, if ever, fade. 

149. Kinds of Colors.— Most, if not all, of the coloring materials 
sold under the name of “mortar colors,” or stains, consist of mineral 


LIMES, CEMENTS AND MORTARS. 123 


pigments put up either in the form of a dry powder or in the form 
of a pulp or paste. 

Pulp colors are said to be susceptible of more uniform mixing with 
the mortar than dry colors, and, as a rule, appear to have the prefer- 
ence for the better grades of work. 

Paste or pulp stains should not be allowed to freeze, and should be 
kept moist by covering with water. 

A great deal of colored mortar is made by using Venetian red, or 
the cheap grades of mineral paints for the coloring matter. The ordi- 
nary Venetian red is very apt to fade and also weakens the mortar, 
and the cheaper grades of mineral colors are not much better. The 
cost of the coloring matter is so small an item that only the very best 
grades should be used. 

Among the brands of mortar colors generally recognized as belong- 
ing to the first grade are the Clinton,” “~ Peerless,” “Pecora”’ 
“Edinburgh,” “‘ American Seal,” “ Milwaukee’ and “Cabot.” 

The principal colors used are red, brown, buff and black, although 
green, purple, gray and drab mortar colors are also made. 

150. Mixing.—Mortar colors, whether in dry or paste form, 
should not be mixed with lime until the latter has been slaked at 
least twenty-four hours, and the best way is to keep a lot of lime putty 
on hand and mix the color with it as needed. 

The color should be thoroughly and evenly mixed with the putty 
before the sand is added, and for very fine work the colored putty 
should be strained through a coarse sieve. 

For cement work the stain should be thoroughly mixed with the 
sand or gravel and set aside in barrels, and the cement added in 
small quantities as required for use. 

Like all water paints, the color of the mortar looks different in the 
bed than when dry. ‘To get the final color of the mortar a little 
should be taken from the bed and permitted to dry thoroughly, when 
the permanent color may be seen. 

The amount of coloring matter required to stain a given quantity 
of mortar varies with the different colors and brands. The following 
quantities may be taken as the average amounts required in laying 
one thousand face brick: 

Red or terra cotta, 50 pounds. 

Buff, brown or French gray, 25 pounds. 

Black, 22 pounds. 


CHAPTER V. 


BUILDING STONES. 


It is important that an architect should have some knowledge of 
the nature of the different kinds of stone, that he may know what 
stone is best to use under any given circumstances, and what stones 
not to use. It can hardly be expected that an architect shall be a 
geologist, a mineralogist or a chemist, and thus capable of determin- 
ing the exact composition of a stone, but it is expected of him that 
he shall know enough of the subject to specify stones that shall have 
sufficient strength and durability and that will not become discolored 
through chemical changes in their constituents. 


To acquire such a knowledge of building stones requires not only 
a study of their mineral constituents and of their structure, but also 
accurate observation and much experience with stones. 


The following short description of the principal building stones of 
this country, with the localities in which they are quarried, will enable 
the young architect to get some idea of their composition and char- 
acteristics, and, it is hoped, assist him in making a judicious selection 
of stones for special cases.* The stones are classed according to 
their structure and composition. 


151. Granite, Gneiss and Syenite.—The granites are massive 
rocks occurring most frequently as the central portions of mountain 
chains. They are a hard, granular stone, composed principally of 
quartz, feldspar and mica, in varying proportions. When the stone 
contains a large proportion of quartz it is very hard and difficult to 
work. When there is a considerable proportion of feldspar the stone 
works more easily. 


The color of the granite is principally determined by the color of 
the feldspar, but the stone may also be light or dark, according as it 
contains light or dark mica. The usual color of granite is either a 
light or dark gray, although all shades from light pink to red are 
found in different localities. 

* For a complete work on the subject the reader is referred to ‘‘ Stones for Building and Dec. 


oration,’”’ by George P. Merril, Ph.D.; John Wiley & Sons, publishers. Much valuable infor. 
mation relating to building stones may also be found in the various numbers of Szone. 


BUILDING STONES. 125 


The light fine-grained stones are the strongest and most durable, 
although almost every granite has sufficient strength for ordinary 
building construction. It generally breaks with regularity and may 
be readily quarried, but it is extremely hard and tough and works 
with great difficulty, so that it is a very expensive stone to use for cut 
work. It is impossible to do fine carving in most granites. Granite is 
one of the best stones for foundations, base courses, water tables, etc., 
and for columns and all places where great strength is required; also 
for steps, thresholds and for flagging, when it can be slit readily. 


Excellent varieties of granite may be obtained in any of the New 
England States and in most of the Southern States and the Rocky 
Mountain region, and in California and Minnesota. 


As a rule granite can be quarried in any size desired. New quar- 
ries should be analyzed to see if they contain iron, in which case it 
would be dangerous to use the stone for ornamental purposes until its 
weathering qualities have been thoroughly tested by exposing blocks 
for a long time to the weather. If the iron is a sulphurate it is quite 
sure to stain the stone. 


Gnetss (pronounced like nice) has the same composition as granite, 
but the ingredients are arranged in more or less parallel layers. On 
this account the rock split in such a way as to give parallel flat sur- 
faces, which renders the stone valuable for foundation walls, street 
paving and flagging. Gneiss is generally taken for granite, and is 
frequently called by quarrymen stratified or bastard granite. 


Syenite is a rock also resembling granite, but containing no quartz. 
It is a hard, durable stone, generally of fine grain and light gray 
color. The principal syenite quarries in this country are near Little 
Rock, Arkansas.* 


All three of these stones are badly affected by fire, large pieces 
breaking off and the stone cracking badly. 


Fox Island, Me.; Groton, Conn.; Woodstock, Md.; St. Cloud, Minn., and Nova 
Scotia granites are spoiled at goo® F. Hallowell, Me.; Red Beach, Me.; Oak Hill, 
Me., and Quincy, Mass., granites are spoiled at 1,000° F. The granites stand- 
ing the highest fire tests are: Barre, Vt.; Concord, N. H.; Ryegate, Vt.; Mt. 
Desert, Me. 


*In many books and papers treating on granite, syenite is described as a rock consisting of 
quartz, feldspar and hornblende, the latter taking the place of the mica in the true granites. 
According to the modern methods of classification such rocks are called ‘‘ hornblende granite.” 

““'The name ‘syenite’ takes its origin from Syene, Egypt, but the stone from which it was 
named has been found to contain more micathan hornblende. According to recent lithologists 
the Syene rock is a hornblende, mica granite, while true syenite, as above stated, is a quartzless 
rock.”’—WMerrild. 


126 BUILDING CONSTRUCTION. 


152. Description of some of the best known Granites. 


Vinalhaven, Fox Island, Me.—These quarries are the most extensive in the 
country ; texture of stone rather coarse; color, gray; contains a small amount of 
hornblende. It takes a good and lasting polish, and is well adapted for all manner 
of ornamental work and general building purposes. The stone has been used exten- 
sively all over the country for both building and monumental purposes. 

Hallowell, Me.—This stone is celebrated for its beauty and fine working quali- 
ties, and is in great demand for monuments and statuary. It is a fine light gray 
rock, comparatively pure, the principal constituents being quartz, feldspar and mica. 
Has been used extensively all over the country. 

There are many other quarries of fine granite in Maine. 

Quincy, Mass.—The Quincy granite quarries are amongst the oldest in the coun- 
try. The product is, asa rule, dark blue-gray in color, coarse grained and hard. 
Composition: quartz, hornblende and feldspar. The polished stairways and pilas- 
ters in the new City Hall at Philadelphia are of this stone. 

Concord, N. H.—A fine-grained granite, light gray color, with a silver lustre; 
well-developed rift and grain, and remarkable for the ease with which it can be 
worked. Constituents: opaque quartz, soda feldspar and white mica. Well adapted 
for statuary and monumental purposes, as well as for general building. The stone 
is eminently durable, the New Hampshire State House, built of this stone in 1816-19, 
being still in an excellent state of preservation. The Congressional Library build- 
ing, Washington, D. C., is built of this stone. 

North Conway, N. H.—A coarse-grained granite; colors, red and green, the red 
being the principal variety. Contains both hornblende and pyroxene. Used in the 
Union Depot, Portland, Me. 

Westerly, R. /.—Granite of fine grain and even texture and of excellent quality. 
Constituents: quartz, feldspar and mica, with some hornblende. Color, rich light 
gray or pink, with a distinct tint of brown when polished. 

Jonesborough, Me.—At this place is quarried a pink or reddish granite, which is 
generally considered as the best American red granite at present quarried. The 
stone is very compact and hard, and much finer in texture than the celebrated red 
Scotch granite. 

St. Cloud, Minn.—Both gray and red granites are quarried at this place; the lat- 
ter greatly resembles the Scotch granite in color, grain and polish. The gray gran- 
ite is about one-third quartz and two-thirds feldspar. 

Graniteville, Mo.—Here is quarried a very hard red granite, mottled with gray 
and black, which takes a handsome polish. The stone has been used in many 
important buildings in St. Louis, Kansas City and Chicago. 

Colorado.—This State also contains great quantities of granite, which, however, 
have been but little developed. The principal quarry is at Gunnison, which pro- 
duces a blue-gray granite, which may be seen in the Colorado State House. 

Georgia.—Excellent grades of light and dark gray granite are contained in this 
State, but as yet they are developed only to a small extent. 


153. Limestone.—This name is commonly used to include all 
stones which contain lime, though differing from each other in color, 
texture, structure and origin. All limestones used for building pur- 
poses contain one or more of the following substances, in addition to 


BUILDING STONES 127 


lime: Carbonate of magnesia, iron, silica, clay, bituminous matter, 
mica, talc and hornblende. 

There are three varieties of limestone used for building purposes, 
viz.: Oolitic limestone, magnesian limestone and dolomite. 

Oolitic limestones are made up of small rounded grains (resembling 
the eggs of a fish) that have been cemented together with lime to form 
a solid rock. 

Magnesian limestones include those limestones which contain ro per 
cent. and over of carbonate of magnesia. 

Dolomite is a crystalline granular aggregation of the mineral dolo- 
mite, and is usually whitish or yellowish in color. It is generally 
heavier and harder than hmestone. 

All varieties of limestone are liable to contain shells, corals and 
fossils of marine animals, more or less pulverized. A limestone can 
be identified by its effervescence when treated with a dilute acid. 

Many of our finest building stones are limestones, but as they are 
less easily and accurately worked than sandstones they are not so 
largely used except in the localities where the best varieties are 
found. | 

The color of limestone is generally a light gray, though it is some- 
times a deep blue, and occasionally of a cream or buff color. The 
light gray varieties often resemble the light, fine-grained granites in 
appearance. 

Most of the granular limestones are susceptible of a high polish. 

Good limestone should be of a fine grain and weigh about 145 
pounds per cubic foot. | 

The limestones described below are very durable, but the hght- 
colored stones are apt to become badly stained in large cities, and 
especially in those cities in which soft coal is used. 

All kinds of limestone are, destroyed by fire, although some varie- 
ties will stand a greater degree of heat without injury than others. 

154. Description of Limestones.—The limestones most exten- 
sively used for building purposes come from the States of Illinois, 
Indiana, Ohio, New York and Kentucky. 


The most celebrated American limestone is that quarried-at Ledford, Indiana, 
which is a light-colored oolite, consisting of shells and fragments of shells (so mi- 
nute as to be scarcely discernible by the naked eye), cemented together by carbonate 
of lime. 

This stone is most remarkably uniform in grain and texture, is exceedingly bright 
and handsome in color, and is less liable to discolor than most light stones. 

It is equally strong in vertical, diagonal and horizontal directions, and when first 
quarried is so soft as to be readily worked with a saw or chisel ; it hardens, however, 


128 BUILDING CONSTRUCTION. 


on exposure, and attains a strength of 10,000 to 12,000 pounds per square inch. 
Owing to its fine and even grain and ease in cutting in any direction, it is especially 
adapted for fine carving. The stone is also very durable. 

On account of its many excellent qualities it was selected by the architect for Mr. 
George W. Vanderbilt’s palatial residence at Biltmore, N. C. The Auditorium 
Building at Chicago, the Manhattan Life Building, New York; the mansion of Mr. 
C. J. Vanderbilt on Fifth Avenue, New York; the State House at Indianapolis and 
many other prominent buildings are built of this stone. There are several quarries 
of this stone, the products varying somewhat in color and quality. 

A gray limestone is quarried at Lockport, NV. Y., which is extensively used for 
trimmings in that State and some parts of New England. 

There are large quarries of limestone at Dayton and Sandusky, Ohio; Joliet, 
Grafton and Chester, Lllinois, and in the vicinity of Topeka, Kansas. There are 
several small quarries which supply the local demand in various parts of Kansas. 
The Topeka stone can be worked almost as easily as wood, and yet becomes hard 
and durable when placed in the building. 

At Carthage, Jasper County, Missouri, there are extensive quarries of limestone, 
which produce large quantities both of quicklime and building stone. The stone is 
coarse grained and crystalline, takes a good polish, and is well adapted to exterior 
finishing. 

Excellent quarries of limestone also exist at Phoenix, Missouri, the stone being 
shipped to St. Louis, Kansas City and Omaha. 

Kentucky.—This State also contains a great quantity of fine limestone, some varie- 
ties of which are said to be equal, if not superior, to the Bedford stone. The best 
known of the Kentucky limestones is probably the Bowling Green (oolitic) stone, 
quarried at Memphis Junction. This stone is almost identical in composition with 
the celebrated ‘‘ Portland” stone of Great Britain. Its color is light gray. It is as 
readily worked as the Bedford stone, is very durable, and is pre-eminent in its resist- 
ance to the discoloring influences of mortar, cement and soil. 


MARBLE. 

155. Marble is simply a crystallized limestone, capable of taking a 
good polish. 

The scarcity and consequent expense of good marbles have in the 
past prevented them from being used in constructional work, except 
occasionally for columns. Most of the marbles obtained from the 
older quarries also stain so easily that they are considered undesir- 
able for exterior work. 

Since the rapid development of the Georgia and Tennessee mar- 
ble quarries, however, stone from these quarries has been much used 
for exterior finish, and even for the entire facing of the walls. These 
marbles will probably be more extensively used for exterior work in 
the future, as they are exceedingly strong and durable and do not 
stain readily. 

Nearly all varieties of marble work comparatively easy, and the 
fine-grained varieties are especially adapted for fine carving. 


BUILDING STONES. 12g 


They generally resist frost and moisture well, and are admirably 
suited for interior decoration, sanitary purposes, etc., and in clear, 
dry climates make a splendid material for exterior construction. 


The strength of marble varies from 5,000 to 20,000 pounds per 
square inch, and only when used for columns need its strength be 
considered. 

[For the composition and strength of various marbles see tables in 
appendix. | 

156. Description of Leading American Marbles.—Great 
quantities of white and black marble are quarried in this country, 
but nearly all of the beautiful streaked and colored marbles are 
imported. 

The States which produced marble in 1894 were California, 
Georgia, Idaho, Maryland, New York, Oregon, Pennsylvania, Ten- 
nessee and Vermont. 


Vermont Marble.—This State is the greatest producer of marble of any State in 
the Union, the total product in 1889 amounting to $2,169,560, more than the com- 
bined value of all other marbles quarried in the country. 

The largest quarries are at West Rutland and Sutherland Falls (Proctor). 

In texture Vermont marble is, as a rule, fine grained, although some of it is 
coarse grained and friable. In color it varies from pure snowy white through all 
shades of bluish, and sometimes greenish, often beautifully mottled and veined, to 
deep blue-black; the bluish and dark varieties being, as a rule, the finest and most 
durable. 

These marbles are used prineipally for monumental and statuary work, and for 
decorative work, sanitary fittings, tiling, etc., in buildings. 

At Sutherland Falls the stone is very massive, and large blocks are taken out for 
general building purposes. 

Tennessee.—Marble has been quarried in this State since 1838, the principal quar- 
ries being in the vicinity of Knoxville, in East Tennessee. The varieties of marble 
produced from these quarries embrace grays, light pinks, dark pinks, buffs, choco- 
late and drabs. Only the pinks and grays, however, are suitable for general build- 
ing purposes, the darker colors being principally confined to furniture and interior 
work. The stone is 98 per cent. carbonate of lime. The pink and gray varieties are 
well adapted for building purposes, their density and resistance to crushing being 
equal to that of any other marble produced in the world. 

They also offer great resistance to moisture, and are practically impervious to the 
staining or discoloring agencies of the atmosphere, except, perhaps, in large manu- 
facturing centres. Under favorable conditions there appears to be no reason why 
these marbles should not last for ages on the exterior of buildings. The highly col- 

, ored varieties are amongst the handsomest produced in this country. 

Georgia.—This State contains extensive beds of marble, which, however, have 
only recently been quarried on a commercial scale. The quarries, which are situated 
in the northern part of the State, produce: 1st. A clear white marble, bright and 
sparkling with crystals. 2d. A dark mottled white ground, with dark blue mot- 


130 BUILDING CONSTRUCTION. 


tlings ; also a light blue and gray ground, with dark mottlings. 3d. White, with 
dark blue spots and clouds, and a bluish-gray, with dark spots and clouds. 4th. Pink, 
rose tints and green in several shades. The appearance of the Georgia marbles is 
quite different from that of the marbles from the other States. 

The stone is a pure carbonate of lime, entirely free from foreign or hurtful ingre- 
dients. It is remarkably non-absorbing, and absolutely impervious to liquids (even 
ink), atmospheric changes and decay, and not subject to discoloration. If soiled by 
dust or smoke it can be easily cleaned by washing with clean water only so as to look 
as bright as when first finished. 

Georgia marble has been extensively used for monuments and for the interior fin- 
ish of buildings, notably in the new Congressional Library. It is also used more and 
more every year for exterior construction, either as trimmings or for the entire wall. 
It may be seen in the exterior of the Ames Building at Boston, the Equitable Building 
at Baltimore, St. Luke’s Hospital at New York and many other prominent buildings. 

New York. 
York City which furnish good building marble, but not quite good enough for dec- 
orative work. Much of it has been used for building purposes in New York City. 

The best quality of black marble is quarried at Glens Falls, on the Hudson River. 
In Montgomery County, Pennsylvania, are several quarries of a granular white and 
mottled marble, which have furnished a great deal of marble for Philadelphia 





There are several quarries of gray, blue and white marble near New 


buildings. 

Colorado and California also contain beautiful varieties of marble, which it is 
thought may in time take the place of much of the foreign marble now imported. At 
present only a very few quarries are worked, and these only to a slight extent. 


157. Onyx Marble.—These stones are of the same composition 
as common marbles, but were formed by chemical deposits instead 
of in sedimentary beds, crystallized by the action of heat. “They 
owe their banded structure and variegated colors to the intermittent 
character of the deposition and the presence or absence of various 
impurities, mainly metallic oxides. The term onyx as commonly 
applied is a misnomer, and has been given merely because in their 
banded appearance they somewhat resemble the true onyx, which is 
a variety of agate.” 

Owing to their translucency, delicacy and variety of colors, and 
the readiness with which they can be worked and polished, the onyx 
marbles are considered the handsomest of all building stones, and 
they also bring the highest price, the cost per square foot for slabs 1 
inch thick varying from $2.50 to $6. Their use is confined to inte- 
rior decoration, such as wainscoting, mantels, lavatories, and for 
small columns, table tops, etc. Most of the onyx marble used in the 
United States is imported from Mexico, although considerable onyx 
is quarried at San Luis Obispo, California, and quarries of very beau- 
tiful stone have recently been opened near Prescott, Arizona. The 
Mexican onyx presents a great variety of colors, creamy white, amber 


CLC GST OES: | 131 


yellow and light green, generally more or less streaked or blotched 
with green or red. Some of the light stones have a beautiful trans- 
lucent clouded effect.’ When cut across the grain the stone often 
presents a beautifully banded structure like the grain of wood. Cut- 
ting the stone across the grain, however, greatly weakens its strength, 
so that it is necessary to back it with slabs of some stronger marble. 


The San Luis Obispo stone is nearly white, finely banded, trans- 
lucent, and takes a beautiful surface and polish. 


The Arizona stone presents a greater variety of coloring, from 
milky white to red, green, old gold and brown, intermingled in every 
possible way. But a comparatively small amount of this stone is as 
yet on the market, but further developments will probably result in 
the production of a great quantity of the stone. 


158. Sandstones.—“ Sandslones are composed of rounded and 
angular grains of sand so cemented and compacted together as to 
form a solid rock. The cementing material may be either silica, car- 
bonate of lime, an iron oxide or clayey matter.” 


They include some of the most beautiful and durable stones for 
exterior construction, and on account of the ease with which they 
can be worked and their wide distribution throughout the country, 
are more extensively used for exteriors than any other stone. 


The grains of sand themselves are nearly the same in all sand- 
stones, being generally pure quartz, the character of the stone 
depending principally upon the cementing material. If the cement- 
ing material is composed entirely of silica, the rock is light colored 
and generally very hard and difficult to work. When the grains have 
been cemented together by fusion or by the deposition of silica 
between the granules, and the whole hardened under pressure, it is 
almost the same as pure quartz and is called gwartztte—one of the 
strongest and most durable of rocks. “If the cementing material is 
composed largely of iron oxides the stone is red or brownish in color 
and usually not too hard to work readily. When the cementing 
material is carbonate of lime the stone is light colored or gray, soft 
' and easy to work.” Such stones do not as a rule weather well, as the 
" cementing material becomes dissolved by the rain, thereby loosening 
the grains and allowing the stone to disintegrate. Clay is still more 
objectionable than lime as a cementing material, as it readily absorbs 
water and renders the stone lable to injury by frost. 


- In some sandstones part of the grains consist of feldspar and mica, 
which have a tendency to weaken the stone. 


132 BOUILDING CON STROCTIOCN. 


Sandstones are of a great variety of colors; brown, red, pink, gray, 
buff, drab or blue, in varying shades, being common varieties ; the 
color being due largely to the iron contained in the stone. The 
oxides of iron do no harm in the stone, but no light-colored sandstone 
should be used for exterior work which contains zvon pyrites (or sul- 
phate of iron), as the iron is almost sure to stain or rust the stone. 


Sandstones vary in texture from almost impalpable fine-grained 
stores to those in which the grains are like coarse sand. All other 
conditions being the same, the fine-grained stones will be the strongest 
and most durable and take the sharpest edge. Sandstones being of 
a sedimentary formation, they are often laminated, or in layers, and 
if the stone is set “‘on edge,” or with its natural bed or surface par- 
allel to the face of the wall, the surface of the stone is quite sure in 
time to disintegrate or peel off. All laminated stones should always be 
laid on their natural bed. When freshly quarried, sandstones gener- 
ally contain a considerable quantity of water, which makes them soft 
and easy to work, but at the same time very liable to injury by freez- 
ing if quarried in winter weather. Many Northern quarries cannot 
be worked in winter on this account. Most, if not all, sandstones 
harden as the quarry water evaporates, so that many stones which are 
very soft when first quarried become hard and durable when placed | 
in the building. Such stones, however, should not be subjected to 
much weight until they have dried out. 


%” 


There is a great abundance of fine sandstone of all colors distributed 
throughout the United States, so that it is not difficult to get a first- 
class stone for any building of importance. Most of the sandstones 
in the Eastern part of the country are either red or brown in color 
there being no merchantable light sandstones east of Ohio. 


159. The following are the best known sandstones in this country, 
any of which are good building stones: 


Connecticut brownstone includes all the dark brown sandstones quarried in the 
neighborhood of Portland, Conn. It is a handsome dark brown stone, tinted slightly 
reddish, has a fine even rift, is easy to work, and gives a beautiful surface when 
rubbed. This stone is decidedly laminated, and the surface will soon peel if the stone 
is set on edge. When laid on its natural bed, however, it is very durable. This 
was the first sandstone quarried in the country, and great quantities of it have been 
used in New York City. 

Longmeadow Stone.—This is a reddish-brown sandstone quarried principally at 
East Longmeadow, Mass. It is an excellent building stone, without any apparent 
bed, and may be cut any way. It varies from quite soft to very hard and strong 
stone, and should be selected for good work. It has been largely used throughout 
the New England States for the past fifteen years, 


BUIEDING STONES. 133 


Potsdam Red Sandstone, from Potsdam, N. Y., is a quartzite and one of the best 
building stones in the country, being extremely durable and equal to granite in 
strength. It was used in the buildings of Columbia College, New York City; All 
Saints Cathedral, in Albany, and in the Dominion Houses of Parliament, in Ottawa, 
Canada. There are three shades, chocolate, brick-red and reddish-cream, 

Hummelstown Brownstone, from Hummelstown, Pa., is a medium fine-grained 
stone, bluish-brown or slightly purple in color, the upper layers being more of a red- 
dish-brown and much resembling the Connecticut stone. The stone compares very 
favorably with the other brownstones mentioned, and is in very general use in the 
principal Eastern cities. 

North Carolina, West Virginia and Indiana contain quarries of brownstone which 
supply the local demand and which are worthy of a wider distribution, particularly 
that of North Carolina. | 

Fond du Lac, Minnesota, furnishes a reddish-brown sandstone closely resembling 
the Connecticut brownstone, but much harder and firmer. ‘‘The stone consists 


_ almost wholly of quartz cemented with silica and iron oxides.” 


Ohio Stone.—The finest quality of light sandstone in the United States is quarried 
in the towns of Amherst, Berea, East Cleveland, Illyria and Independence, Ohio, 
and is commonly known as Ohio stone or Berea stone. It is a fine-grained, homo- 
genous Sandstone, of a very light buff, gray or blue-gray color, and very evenly 
bedded. The stone is about 95 per cent. silica, the balance being made up of small 
amounts of lime, magnesia, iron oxides, alumina and alkalies. There is but little 
cementing material, the various particles being held together mainly by cohesion 
induced by the pressure to which they were subjected at the time of their consolida- 
tion, They are very soft and work readily in every direction, and are especially 
fitted for carving. 

‘‘Unfortunately the Berea stone nearly always contains more or less iron pyrites 
and needs to be selected with care. Most of the quarries, however, have been tray- 
ersed by atmospheric waters to such a degree that all processes of oxidation which 
are possible have been very nearly completed.” * 

The stone can be furnished in blocks of any desired size and of uniform color. 
The stone is shipped to all parts of the country, and is in great demand for fine 
buildings. Mr. H. H. Richardson, the celebrated architect, often used it in con- 
trast with the Longmeadow sandstone for trimmings and decorative effects. The 
stone contains from about 6 to 8 per cent. of water when first taken from the quarry, 
and about 4 per cent. when dry. The stone cannot be quarried in winter on account 
of the splitting of the stone caused by the freezing of the water contained in it. 
There are some fourteen or fifteen different companies that quarry this stone for the 
market. 

‘“ The Waverly sandstone comes from Southern Ohio. This is a fine-grained, 
homogenous stone of a light drab or dove color, works with facility, and is very 
handsome and durable. It forms the material of which many of the finest buildings 
in Cincinnati are constructed, and is, justly, highly esteemed there and elsewhere.”’+ 

Ohio is the largest producer of sandstone of any State in the Union. 

At Warrensburg, Mo., is quarried a gray sandstone which has been used in many 
important buildings in Kansas City. 


* ‘Stones for Building and Decoration,”’ pp. 276-277. 
+ Baker, ‘‘ Masonry Construction,”’ p. 30. 


134 BUILDING CONSTRUCTION. 


The Rocky Mountain region also furnishes great quantities of fine sandstones. In 
Arizona is quarried a very fine-grained chocolate sandstone, which takes a fine edge 
and is excellently adapted for rubbed and moulded work. A considerable quantity 
of it is used in Denver, Col., on account of its pleasing color, and it is also shipped 
east of the Missouri River. 

At Manitou, Col., are inexhaustible quarries of a fine red stone, much resembling 
the Longmeadow stone of Massachusetts, but of a lighter red color. It has no appar- 
ent bed and weathers well. It has sufficient strength for ordinary purposes. At Fort 
Collins, Col., is quarried a much harder and slightly darker stone, which is an excel- 
lent stone for almost any purpose. It has sufficient strength for piers and columns, 
and is hard enough for steps and thresholds. It is much harder to cut than the 
Manitou stone, and hence is more expensive, but it is more durable. This stone has 
been shipped as far East as New York City. Colorado also contains an inexhaustible 
supply of sandstone flagging, admirably adapted for foundations and sidewalks; it is 
as strong as granite, and may be quarried in slabs of almost any size or thickness. 

A red and buff sandstone is quarried at Glenrock, Wyoming, which has been used 
in Omaha, Nebraska. 

California has fifteen quarries of sandstone, the larger number of which are in 
Santa Clara County. Stanford University is built of a light-colored sandstone quar- 
ried at San Jose, Cal. 

Owing to the sparsely settled condition of the country and the lack of railroad 
facilities, the building stones of the Western portion of the United States have been 
but little developed, but with the building up of the country the quarrying industry 
will undoubtedly become one of great importance. 


160. Lava Stone or Turfa.—Near Castle Rock, in Colorado, 
is quarried a soft, very light gray and pink stone of volcanic origin, 
which is commonly called lava stone. It is extremely light in weight, 
weighing only about 110 pounds per cubic foot, and can be cut with 
a knife. It weathers better than the soft sandstones, and its color 
makes it very suitable for rock face ashlar. It is difficult to obtain in 
large blocks, and is full of clay or air holes and often of invisible 
cracks, which render it dangerous for use in heavy buildings, but for 
dwellings it makes a very cheap, durable and pleasing stone. Owing 
to the small air holes which it contains it does not receive a finished 
surface, and is most effective when used rock face. There are a 
great many houses and several public buildings in Denver built of 
this stone. A similar stone occurs in the vicinity of the Las Vegas 
Hot Springs, and Albuquerque, New Mexico. 


Blue Shale is a variety of sandstone that is dark blue in color, 
quite dense and hard, and makes a fair material for foundations. As 
a rule it does not work readily and often contains iron pyrites, which 
renders it unsuitable for ashlar or trimmings. 

The only stone in many localities is a hard, igneous rock, called 
trap, which is suitable for foundations, but cannot be cut easily. 


BUILDING STONES. 135 


Such stones are only used for local purposes when no other can be 
obtained except at great expense. 

161. Slate.—Although slate is not strictly a building stone, yet it 
is largely used for covering the roofs of buildings, for blackboards, 
sanitary purposes, etc., and the architect should be familiar with its 
qualities and characteristics. 

The ordinary slate used for roofing and other purposes is a com- 
pact and more or less metamorphosed siliceous clay. Slate stones 
originated as deposits of fine silt on ancient sea bottoms, which in the 
course of time became covered with thousands of feet of other mate- 
rials and finally turned into stone. 

“The valuable constituents in slate are the silicates of iron and 
alumina, while the injurious constituents are sulphur and the carbon- 
ates of lime and magnesia.” 

One of the most valuable characteristics of slate is its decided ten- 
dency to split into thin sheets, whose surfaces are so smooth that they 
lie close together, thus forming a light and impervious roof covering. 
These planes of cleverage are caused by intense lateral pressure, and 
are generally at very considerable though varying angles with the 
ancient bedding. 

The most valuable qualities of slate are its strength, toughness and 
non-absorption. 

Strength and Hardness.—¥rom various tests that have been made 
on the quality of slate, it appears that, in general, the strongest spec- 
imens are the heaviest and softest, as also the least porous and cor- 
rodible. “The tests for strength and corrodibility are probably those 
of greatest importance in forming an opinion regarding the value of 
the slate under actual conditions of service.” * 

Mr. Mansfield Merriman suggests that specifications should require 
roofing slates to have a modulus of rupture for transverse strength 
greater than 7,000 pounds per square inch. 

If the slate is too soft, however, the nail holes will become enlarged 
and the slate will get loose. If it is too brittle the slate will fly to 
pieces in the process of squaring and holing, and will be easily broken 
on the roof. “A good slate should give out a sharp metallic ring 
when struck with the knuckles ; should not splinter under the slater’s 
axe ; should be easily ‘holed’ without danger of fracture, and should 
not be tender or friable at the edges.” 

The surface when freshly split should have a bright metallic lustre 
and be free from all loose flakes or dull surfaces. 


* Mansfield Merriman in Stone, April, 1895. 


136 BOUIIDING CONSTRUCTION. 


Color.—The color of slates varies from dark blue, bluish-black and 
purple to gray and green. ‘There are also a few quarries of red slate. 
The color of the slate does not appear to indicate the quality. The 
red and dark colors are generally considered the most effective, and 
the greens are generally used only on factories, storehouses and 
buildings where the appearance is not of so much importance. 

Some slates are marked with bands or patches of a different color, 
and the dark purple slates often. have large spots of hight green upon 
them. These spots do not as a rule affect the durability of the slate, 
but they greatly detract from its appearance. 

As a rule the dark color of slate, particularly that of the slates of 
Maine and Pennsylvania, appears to be due to particles of carbona- 
ceous matter contained in the slate. 

“The red slates of New York are made up of a ground mass of 
impalpable red dust in which are imbedded innumerable quartz and 
feldspar particles.”’ 

Absorption.—A good slate should not absorb water to any percep- 
tible extent, and if a slate is immersed in water half its height the 
water should not rise in the upper half; if it does it shows that the 
slate is not of good quality. 

“Tf, upon breathing upon a slate, a clayey odor be strongly emitted, 
jt may be inferred that the slate will not weather.” 

Grain.—A good slate should have a very fine grain, and the slates 
should be cut lengthways of the grain, so that if a slate breaks on the 
roof it will not become detached, but will divide into two slates, each 
held by a nail. 

Market Qualities —The market qualities of slate are classed accord- 
ing to their straightness, smoothness of surface, fair, even thickness, 
and according to the presence or absence of discoloration. 

Uses.—The principal use of slate is for roofing purposes, but it is 
also used for billiard tables, mantels, floor tiles, steps, flagging, fit- 
tings for toilet rooms, and for school blackboards. 

162. Distribution and Varieties of Slate.—The distribu- 
tion of the slate industry among the different States in 1890 is best 
shown by the following figures, which give the value of the product : 

Pennsylvania, $2,011,776; Vermont, $838,013 ; Maine, $214,000 ; 
New York, $130,000; Maryland, $110,008; Virginia, $85,079; 
Georgia, $15,330; Michigan, $15,000; California, $13,889; New 
Jersey, $10,985 ; Arkansas, $240. 

Slates are classified in the trade, however, by the name of the 
region in which they are quarried, some regions extending into two 


BUILDING STONES. 137 


or more States, while several regions are contained in the State of 
Pennsylvania. The product from each region is more or less distinc- 
tive from that of other regions. The more important producing 


regions are: 
Number of 
Quarries. Product. 


Vermont and New York region...3.........+ee0+-- 76 $968,616 


ABE TeaIOM, PONS V Vania Gaiias < svn10 5 © tinea se a= 20 707, 162 
Penionregion sPennsyivatiasgcc. crsass vies oes sss 45 690, 432 
Pen Arey! recion, Pennsylvaniacws.. sas.c0s seen cee 04 17 393,030 
DASE BOON lag rege cere ol Likes mss weiss. 6 ste: Vi SSS, #8 «wis 4 214,000 
Northampton hard-vein region, Pennsylvania,....... 18 184,595 
Peach Bottom on paten and cane ae Spiess 146,565 
Virginia regiorf, . ne ON Taree ten re aeaten wire sie 3 85,079 


The slates of the Bangor, Pen es and Lehigh regions and the 
Northampton hard veined slates are found in the extensive slate for- 
mation known as the Hudson River Division of the lower Silurian 
deposits, while the slate formations of Vermont and New York, 
Maine and the Peach Bottom region, probably belong to the Cam- 
brian Division, whose place in the geological series is lower and older 
than the Silurian rocks. 

“The slates of the Cambrian formation are usually regarded as 
better in respect to strength and weathering qualities than those of 
the Silurian age, the market price of some varieties of the former 
being, indeed, more than double that of the common kinds of the 
latter 


Vermont and New York Region.—In the western portion of Vermont are 
extensive quarries of slate, the product being used for all the different purposes for 
which the material is adapted. 

The stone is soft and uniform in texture, and can be readily planed or sawed with 
a circular steel saw like wood. 

The slates from this region vary greatly in color, and are classified and sold under 
the following names: 

Sea-green, unfading green, uniform green, bright green, red, bright red, purple, 
variegated and mottled. 

The true sea-green slate is found only in this State, but it fades and changes color 
badly. 

Red Slate,.—Nearly all the red slate used in the United States is quarried in the 
neighborhood of Granville, near the Vermont line, in New York State. ‘‘ The slates 
of this formation are of a brick-red and green color, both varieties often occurring in 
the same quarry.” The slate is of good quality and is almost entirely used for roof- 
ing purposes, its color making it especially desirable for fine residences and public 
buildings. Owing to the limited quantity, this slate brings about three times the 
price of the dark slates. 

Maine Region.—The quarries in this region are located at Monson, Blanchard 
and Brownville, Piscataquis County. The stone is of a blue-black color, of excel- 


138 BOLEDINGACON SLAG Gil OW. 


lent quality, being hard, yet splitting readily into thin sheets with a fine surface. 
They are not subject to discoloration, and give forth a clear ringing sound when 
struck. The Brownville slate is said to be the toughest slate in the world. Slate 
from this quarry, after fifty years’ exposure, looks as bright and clean as when new. 


The Maine quarries furnish nearly all the black slates used in New England. 
The product is also extensively used for slates, blackboards and sanitary purposes. 

163.— 

Pennsylvania Slates.—Bangor Reyion.—This region is entirely within North- 
ampton County, and is the most important, in point of production, in the country. 
The principal quarries are at Bangor, East Bangor and Slatington. The color is 
a uniform dark blue or blue-black. This slate is used very extensively for black- 
boards and school slates, as well as for roofing purposes. Average modulus of rup- 
ture, 9,810 pounds. 

The Lehigh region includes Lehigh County entire and a few quarries in Berk and 
Carbon Counties and opposite Slatington in Northampton County. The product is 
similar to that of the Bangor region. 


Pen Argyl region embraces quarries at Pen Argyl and Wind Gap in Northamp- 
ton County. 


The Northampton hard-vein region includes the Chapman, Belfast and other 
quarries, allin Northampton County. This region is distinguished on account of 
the extreme hardness of the slate as compared with that produced in other regions of 
the State. The product is considered as the best of the Silurian slates, its extreme 
hardness being generally considered as an advantage to the slate, rendering it dur- 
able and non-absorptive. It is especially suitable for flagging. Average modulus 
of rupture, about 8,480 pounds. 


Peach Bottom Region.—The celebrated ‘‘ Peach Bottom Slate” is taken from a 
narrow belt scarcely 6 miles long and a mile wide, extending across the southeastern 
portion of York County and into Hartford County, in Maryland. The stone is 
tough, fine and moderately smooth in texture, blue-black in color, and does not fade 
on exposure, as has been proven hy seventy five years’ wear on the roofs of build- 
ings. It also ranks very high for strength and durability, and is generally consid- 
ered equal, if not superior, to any slate in the country. The average modulus of 
rupture of twelve Specimens was II, 260 pounds, the lowest value being 8,320 pounds. 


The northern peninsule of {dichigan contains an inexhaustible supply of good 
roofing slate, and extensive quarries have been opened about 15 miles from L’ Anse 
and about 3 miles from Huron Bay. ‘‘ The stone here is susceptible of being split 
into large, even slabs of any desired thickness, with a fine, silky, homogenous 
grain, and combines durability and toughness with smootnness. Its color is an 
agreeable black and very uniform.” * 

A gocd blue-black roofing slate is quarried in Bingham County, Virginia, which 
bids fair to supplant other slates in that section of the country. 

Quarries in Polk County, Georgia, furnish most of the roofing slates for Atlanta 
and neighboring towns. 

Good roofing slate is also known to occur in California, Colorado and Dakota, 
but the first State mentioned is the only one in which quarries have yet been opened. 


* “* Stones for Building and Decoration,” p. 302. 


BUILDING STONES. 139 


164. Soapstone.—Although not properly a building stone, soap- 
stone is used more or less in the fittings of buildings, especially for 
sinks and wash trays, and for the linings of fireplaces. 


Soapstone is a dark bluish-gray rock, composed essentially of the 
mineral talc. . 

The stone is soft enough to be cut readily with a knife, or even 
with the thumb nail, and has a decided soapy feeling, hence its name. 


Although so soft, this stone ranks amongst the most indestructible 
and lasting of rocks. At present its chief use is in the form of slabs 
about 1} inches thick, for stationary washtubs and sinks, for which it 
is one of the best materials. Soapstone also offers great resistance to 
heat, and is often used for lining fireplaces. 


At one time it was extensively used in New England in the manu- 
facture of heating stones. Considerable quantities of powdered soap- 
stone are used for making slate pencils and crayons, as a lubricant for 
certain kinds of machinery, and in the finishing coat on plastered 
walls. 

The principal quarries producing block stone are situated in the 
States of New Hampshire, Vermont and Pennsylvania. 


The State of North Carolina produces most of the powdered soap- 
stone, which is quarried in small pieces and ground in a mill. 


SELECTION OF BUILDING STONES. 


165. The selection of a stone for structural purposes is a matter of 
the greatest importance, especially when it is to be used in the con- 
struction of large and expensive buildings. The cities of Northern 
Europe are full of failures in the stones of important structures, and 
even In the cities of the Northern portion of the United States the 
examples of stone buildings which are falling into decay are only too 
numerous. : 


“The most costly building erected in modern times—the Parlia- 
ment House in London—was built of a stone taken on the recom- 
mendation of a committee representing the best scientific and tech- 
nical skill of Great Britain. The stone selected was submitted to 
various tests, but the corroding influences of a London atmosphere 
were overlooked. The great structure was built (of magnesian lime- 
stone), and now it seems questionable whether it can be made to 
endure as long as a timber building would stand, so great is the effect 
of the gases of the atmosphere upon the stone.” * 


* Baker in ‘‘ Masonry Construction,”’ p. 4. 


140 BUILDING ICON Site OG LTO, 


Stone should be studied with reference to its hardness, durability 
beauty, chemical composition, structure and resistance to crushing. 

166. Climate.—In selecting a building stone the climate, together 
with the location, with especial reference to the proximity to large 
cities and manufacturing establishments, should be first considered. 
There is many a porous sand or limestone which could endure an expos- 
ure of hundreds of years in a climate like that of Florida, New Mexico, 
Colorado or Arizona, which would be sadly disintegrated at the end of 
a single season in one of the Northern States. The climate of our 
Northern and Eastern States, with an annual precipitation of some 39 
or 40 inches and a variation in temperature sometimes reaching 120°, 
is very trying on stonework, and unless a stone is suited to the condi- 
tions in which it is placed, there are few materials more liable to 
decay and utter failure. 

167. Color.—The great governing point with an architect in 
selecting a building stone is generally the color. This again is lim- 
ited to a choice between those stones which come within the limit of 
cost, and should be finally overruled by the question of durability. 
The architect is too apt to think that if a building cannot be pleasing 
both in form and color it had better not be built at all, but he should 
keep in mind not only how the building will look when just com- 
pleted, but how it will appear at the end of a few years, and, again, 
at the end of half a century. It is better that the colors be a little 
harsh and inharmonious at first, if durability is gained thereby, than 
to use the most pleasing color only to see it entirely changed at the 
end of a year, and crumbling in pieces at the end of a decade. 

A durable stone of any color generally tones down and becomes 
more pleasing at the end of a few years, while one that is not durable 
and permanent in color very soon becomes an eyesore. 

In the country and small towns where there is no manufacturing, 
and where little bituminous coal is used, light-colored stones may be 
used with the prospect of their color remaining unchanged ; but in 
large cities and in manufacturing towns, particularly those where 
bituminous coal is the principal fuel, light stones should be avoided, 
and for such localities a red or brown siliceous sandstone is the most 
enduring and permanent, and next to this comes granite. 

In a city like Chicago, the darker the stone used the more perma- 
nent will be its color (that is, in the central portion of the city), as 
both brick and stone assume a dirty, dark bronze color in a few 
years, and in such localities delicate colors and fine carving are out 
of place. 


BUILDING STONES. 141 


In climates like that of Colorado, Arizona and New Mexico, where 
there is a very bright sun and almost no rain, the light stones, and 
particularly marbles, are most effective, as the shadows on such stones 
are very marked, and all kinds of ornament are made much more 
prominent than on red or dark stones, and any compact stone will 
last for centuries above the ground. 

As arule, all else being equal, the stone which holds its native 
color best will be most beautiful in a building, and of the stones 
which change color, that will be most desirable which changes least 
and evenly. 

168. Durability.—Naturally the durability of a stone is of the 
first importance, for unless the stone will last a reasonable length of 
time, the money spent on the structure will be largely wasted, and 
all public buildings should be built of material that is practically 
imperishable. 

The following table, taken from the Report of the Tenth Census, 
1880, Vol. X., p. 391, gives the number of years that different stones 
have been found to last in New York City, without discoloration or 
disintegration to the extent of necessitating repairs : 


GAT SCROEOW IStONE Hae pfowease tits =) tren ects poo eive se vinie ee 5to 15 
Fine laminatedsbrowmnston€.. .cs0 acc: << 6s ee ciss€ Sialsai 0 os 20 to 50 
COmpAc he DOW NSLONG. tan... tebe’ s parece d's os Mins 0 als otes «ne 100 to 200 
Bluestone (sandstone), untried :. 5.2. 2.4.%c4..<00s Probably centuries 
Nova scotia sandstone, untried, — 0,2. .<s «ss sone Perhaps 50 to 200 


Ohio sandstone (best siliceous variety), 
Perhaps from one to many centuries 


(OATS TOSI eETOUS LIMESTONE nies a0 nde ieee s aol oie els 20 to 40 
Pine colic (irench) limestones noc sc .s05 6 nee 4s os 004s 30 to 40 
RiarhlewCeatsevd@lomilleges a ck tks tices cai als'e «eb so abcess 40 
NATOIE HG GOLOMILes te an ote ao Cx alars Sraerels 60 kee vera ces 60 to 80 
Mi Srigleweiinee. Fost oe ce ere ee eke See a ators Ge sda e aire Saale male 50 to 100 
CCEA Ce eerie eta ale Gio cinte aata colts tat ond Sots silicon te oiistets 25.140 ZOO 
TCO 5.5 a oe a Be cy eer ee en Ca ree eee 50 years to many centuries 


There are many circumstances and conditions, aside from the qual- 
ity of the stone, that affect the durability of exposed stonework, the 
more- important of which are heat and cold, composition of the 
atmosphere, position of the stone in the building, and manner of 
dressing the stone. 

169. Heat and Cold.—The most trying conditions to which a 
building stone is subject are the ordinary changes of temperature 
which prevail in the Northern and Eastern States. “Stones, as a 
tule, possess but a low conducting power and slight elasticity. They 


142 BOILDING CONSSARUCTION. 


are aggregates of minerals, more or less closely cohering, each oi 
which possesses degrees of expansion and contraction of its own. As 
temperatures rise each and every constituent expands more or less, 
crowding with resistless force against its neighbor; as the tempera- 
tures decrease a corresponding contraction takes place. Since the 
temperatures are ever changing, often to a considerable degree, so, 
within the mass of the stone, there is continual movement among its 
particles. Slight as these movements may be they can but be con- 
ducive of one result, a slow and gradual weakening and disintegra- 
tion.” * This is supposed to be the chief cause of the disintegration 
of granites. 


There are several examples of old stonework in New York City 
that have begun to decay on the south and west sides, where the sun 
shines the longest, but not on the north and east. The effects of 
moderate temperatures upon stones of ordinary dryness are, however, 
slight when compared with the effects of freezing upon stones satu- 
rated with moisture. The pressure exerted by water passing from a 
liquid to a solid state amounts to not less than 138 tons to the square 
foot ; and it is, therefore, evident that any porous stone exposed to 
heavy rains and a temperature several degrees below the freezing 
point must be seriously damaged by a single season’s exposure. It is 
also evident that the more porous a stone the greater will be the 
deterioration, and as sandstones are the most porous of ali building 
stones they suffer the most from this cause and granites the least, 
hence granite is the best stone for a base course or underpinning. 
[For the effect of absorption on the durability of stones see Sec- 
tion ‘147. | 

170. Stone Set on Bed.—When a stone is built into the walls 
of a building in such a way that the natural layers of the stone are 
vertical, or on edge, the water penetrating the stone and freezing 
causes the surface of the stone to exfoliate or peel off much quicker 
and to a greater extent than it would if the stone had been laid with 
its natural bed horizontal. 

Stones that are so situated in a building that the rain will strike 
and wash over them, such as sills, belt courses, etc., also decay sooner 
than the ashlar forming the face of the wall, and should be of the 
most durable material. 

171. Atmospheric Action.—The chemical action of the gases 
of the atmosphere, when brought by rain in contact with the surface 


* ‘* Stones for Building and Decoration,” p. 353. 


OGILVIE. 143 


of certain stones, seriously affects their durability. The most impor- 
tant changes produced by these agencies are oxidation and solution. 

Oxidation.—The process of oxidation 1s, as a rule, confined to those 
stones which contain some form of iron, and particularly that known 
as pyrite. If the iron exists in the latter shape it generally combines 
with the oxygen of the air, forming the various oxides and carbonates 
of iron, such as are popularly known as “rust.” 

“Tf the sulphide occurs scattered in small particles throughout a 
sandstone the oxide is disseminated more evenly through the mass of 
the rock, and aside from a slight yellowing or mellowing of the color, 
as in certain Ohio sandstones, it doesnoharm. Indeed, it may result 
in positive good, by supplying a cement to the individual grains and 
thus increasing the tenacity of the stone.” * 

If the pyrite exists in pieces of any size, however, it is almost sure 
to oxidize and stain the stone so as to ruin its appearance, especially 
if it is of a light color. 

In all other than sandstones the presence of any pyrite is a very 
serious defect, as it is almost sure to rust the stone and may also ren- 
der it porous and more liable to the destructive effects of frost. 

Solution.—The worst effect of the action of the gases of the atmos- 
phere in connection with rain is in dissolving certain constituents of 
stones, thereby causing their decomposition. Pure water alone is 
practically without effect on all stones used for building, but in large 
cities, and particularly those in which a great deal of coal is con- 
sumed, the rain absorbs appreciable quantities of sulphuric, carbonic 
and other acids from the air and conveys them into. the pores of the 
stone, where they very soon destroy those stones whose constituents 
are liable to be decomposed by such acids. 

Carbonate of lime and carbonate of magnesia, the principal con- 
stituents of ordinary marbles, limestones and dolomites, are particu- 
larly susceptible to the solvent action of these acids, even when they 
are present only in very minute quantities, and on this account these 
stones are extremely perishable in large cities and manufacturing 
towns. Of course in dry climates the acids are not conveyed into the 
stone to any great extent, and the stones last much longer than in a 
damp climate. The less absorbent a stone is the less will be the sol- 
vent action of the acids, and the longer the stone will last. Dolo- 
mites are in this respect more durable than limestones. 

Sandstones, whose cementing material is composed largely of iron 
or lime, are also subject to rapid decay through the solvent action of 





*“ Stones for Building and Decoration,’’ p. 360. 


144 BUILDING CONSTRUCTION. 


the acidulated rains. The feldspars of granites and other rocks are 
also susceptible to the same influence, though in a less degree. 


172. Method of Finishing.—This also has a great deal to do 
with the durability of a stone. As a rule, the less jar from heavy 
pounding that the surface is subjected to, the more durable will be 
the surface, for the reason that the constant impact of the blows tends 
to destroy the adhesive or cohesive power of the grains, and thus ren- 
ders the stone more susceptible to atmospheric influences. This 
apples particularly to granites and limestones. Only granites and 
the hardest sandstones should be pene or bush hammered ; all others, 
if dressed, should be cut with a chisel. Sandstones may afterward 
be finished with a crandal, if desired. For granites a rock-face sui- 
face would probably prove most durable, since the crystalline facets 
thus exposed are best fitted to shed moisture and the natural adhesioa 
of the grains has not been disturbed. For all other stones, howevei, 
a smoothly sawn, rubbed or polished surface seems best adapted to i 
variable climate. 


173. Strength.—Whenever a stone is to be used for foundations, 
piers, lintels, bearing stones, etc., its strength should be considered, 
and if it has not been demonstrated by practical use under similar 
circumstances, cubes of the stone about 6 inches on a side should be 
carefully tested for the crushing strength. If the stone has all the 
appearance of a first-class stone of its kind, its strength may be 
assumed to be equal to the average strength of stones of that kind. 
The safe working strength for piers, etc., should not exceed one-tenth 
of the crushing strength. ‘Tables giving the crushing strength of 
many well-known stones and the safe working strength for stone 
masonry are given in the appendix. 


The method in which a stone is quarried sometimes has much to 
do with its strength. If the stone is quarried by means of explosives 
the stone may contain minute cracks, which cannot be discovered 
until the stone receives its load, when their presence is unpleasantly 
manifested. Such an occurrence could only take place in some stone 
like lava or conglomerates. The cracking and splitting of stones in 
buildings is often due more to zmperfect setting than to lack of 
strength in the stone. Any stone that will meet the requirements for 
durability will have sufficient strength for all purposes, except in the 
positions mentioned above. 7 


Hardness.—For many purposes the hardness of a stone must be 
considered, as when it is to be used for steps, door sills, paving, etc. 


BOILDING STONES. T45 


Granite, quartzite, or siliceous sandstone, and bluestone are the best 
stones for this purpose. 

Cheapness.—This often has more to do with the choice of a 
building stone by the owner than the architect could wish. The cost 
of the stone when cut depends not only upon the cost of the rough 
stone delivered at the site, but also upon the ease with which the 
stone may be worked ; whether the stone is to be smooth or rock 
face; plain or moulded; and also to some extent upon its weight. 
One stone may be cheaper than another in the rough, but the extra 
labor of cutting may make it the most expensive when put in the 
wall. The heavier a stone is the greater will be the cost of setting 
and transportation. . 

174. Fire Resistance.—The ability of a stone to withstand the 
action of fire is often of much consequence, especially when it is 
exposed to fire risks on all sides, as is the case with most business 
blocks. Of the different kinds of stone used for building the com- 
pact, fine-grain sandstones withstand the action of fire the best ; 
limestones and marbles suffer the worst (becoming calcined under an 
intense heat) and granites are intermediate. The best sandstones 
generally come out uninjured, except for the discoloration caused by 
smoke. Granites do not collapse, but the face of the stone generally 
splits off and flies to pieces, often with explosive violence. 

175. New Stones.—If, in selecting a building stone, it is deemed 
advisable to use a stone from a new quarry, and the weathering qual- 
ities of the stone have not been tested by actual use in buildings, the 
architect should insist upon a chemical and microscopic test of the 
stone by an expert to see if there is anything in the composition or 
structure of the stone that would render it unsuited for building pur- 
poses, and if the report is favorable, and the stone meets the tests 
described in the following sections, he may then use it with a free 
conscience. 

An architect cannot be too careful about using a new stone, or one 
_ that has not been used under similar circumstances, and whenever he 
is obliged to use such a stone he should take pains to obtain as much 
- information in regard to it, from all practical sources, as possible. 

The writer has known of a case in which a stone, which had for a 
long time been used for making ashlar, was used in the piers under a 
seven-story building, and the piers commenced to crack under only 
about one-one-hundredth part of the breaking strength of the stone 
as given in a published report of tests on the strength of stone, and 
it cost nearly $200,000 to repair the damage and substitute other 


146 BOLEDING CONS BAU GCTLOIN: 


stone. The faiiure of the stone (which was a lava stone) was sup- 
posed to be due to fine cracks produced in blasting out the stone 
from the quarry. 

It will not always do, either, to rely upon the past reputation of a 
stone for durability, as the quality of building stones from the same 
quarry often differ. 


TESTING OF BUILDING STONES. 


176. Every stone intended for building purposes that does not 
come from some well-known quarry should be tested by chemical 
analysis, and the results compared with the analyses of well-known 
stones of the same kind, and if found to differ materially in constit- 
uents soluble in water or attached by sulphuric or carbonic acids, 
they should be rejected ; the presence of iron pyrites should also lead 
to the rejection of the stone, if intended for external use. If the 
building is one of importance the architect should insist on the own- 
ers getting the opinion of some expert chemist or mineralogist on the 
durability and weathering qualities of the stone. 


As a rule, however, most buildings are now built from stone taken 
from well-known quarries, whose weathering qualities have been 
proved, so that if the quality is equal to the best that the quarry will 
supply the stone will prove all that was expected of it. The fact, 
however, that certain quarries have furnished good material in. the 
past is no guarantee of the future output of the entire quarry. This 
is especially true regarding rocks of sedimentary origin, as the sand 
and limestones, different beds of which will often vary widely in color, 
texture, composition and durability, though lying closely adjacent. 
In many quarries of calcareous rocks in Ohio, Iowa and neighboring 
States, the product is found to vary at different depths, all the way 
from a pure limestone to magnesian limestones and dolomite, and in 
many cases an equal variation exists in point of durability.* 

The architect should, therefore, make a careful examination of the 
stone as it is delivered on the ground, or in the yard before it is cut, 
to see that the quality of the stone is up to the standard, and in large 
buildings in which a great quantity of stone will be required, it will 
be advisable to visit the quarry and determine from which part of 
the quarry the stone shall be taken. 


The following rules and tests will enable one to judge if the stone 
is of a good quality and likely to prove durable: 


* ‘Stones for Building and Decoration,” p. 380. 


BOILDING STONES. 147 


Compactness.—As a general rule, in comparing stones of thé same 
class, the least porous, most dense and strongest will be the most 
durable in atmospheres which have no special tendency to attack the 
constituents of the stone. A good building stone should also give 
out a clear, ringing sound when struck with a hammer. 

Frracture.—A fresh fracture, when examined through a powerful 
magnifying glass, should be bright, clean and sharp, with the grains 
well cemented together. A dull, earthy appearance indicates a stone 
likely to decay. 3 

177. Absorption.—One of the most important tests for the durabil- 
ity of stone is that of the porosity, or degree with which the stone 
absorbs moisture, since, other things being equal, the less moisture a 
stone absorbs the more durable it will be. 

To determine the absorptive power the specimen should be thor- 
oughly dried at about 1oo° F. and carefully weighed ; it must then 
be soaked for at least twenty-four hours in pure water ; when removed 
from the water, the surface allowed to dry in the air and then 
weighed. The increase in weight will be the amount of water 
absorbed, and will stand, although not absolutely correct, as an 
expression of the stone’s absorptive power. ‘This test is extremely 
simple, and when done with care should give very practical results. 

Any stone which will absorb 10 per cent. of its weight of water 
during twenty-four hours should be looked upon with suspicion until, 
by actual experiment, it has shown itself capable of withstanding, 
without harm, the different effects of the weather for several years. 
Half of this amount may be considered as too large when the stone 
.contains any appreciable amount of lime or clayey matter.* 

The porosity of a stone also has influence upon its appearance 
when in the building. 

A non-absorbent stone is washed clean by each heavy rain, and its 
original beauty is retained, while a porous stone soon fills with dirt 
and smoke and looks little better than a wall plastered with cement. 
Even in stones for interior decoration absorption should not be over- 
looked, as ink, oils or drugs may ruin expensive furnishings if the 
stone is porous. 

178. Acid Test.t—Simply soaking a stone for some days in dilute 
solutions containing 1 per cent. of sulphuric acid and of hydrochloric 
acid will afford a rough idea as to whether it will stand a town atmos- 
phere. A drop or two of acid on the surface of the stone will create 


* ** Stones for Building and Decoration,” p. 371. 
+ ** Notes on Building Constructioun,’’ Part III, p. 11. 


148 BOILDINGECONSTLTROGL OW 


an intense effervescence if there is a large proportion present of car- 
bonate of lime or carbonate of magnesia. 

Test for So/ution.—The following simple test is useful for deter- 
mining whether a stone contains much earthy or mineral matter easy 
of solution : 

Pulverize a small piece of the stone with a hammer, put the pul- 
verized stone into a glass about one-third full of clear water, and let 
the particles remain undisturbed at least half an hour. Then agitate 
the water and broken stone by giving the glass a circular motion with 
the hand. If the stone be highly crystalline, and the particles well 
cemented together, the water will remain clear and transparent, but 
if the specimen contains uncrystallized earthy powder, the water will 
present a turbid or milky appearance in proportion to the quantity of 
loose matter contained in the stone. 


SEASONING OF STONE. 


179. All stone is better for being exposed in the air until it 
becomes dry before it is set. This gives a chance for the quarry 
water to evaporate, and in nearly all cases renders the stone harder, 
and prevents the stone from splitting from the action of the frost. 


Many stones, particularly certain varieties of sandstone and lime- 
stone, that are quite soft and weak when first quarried acquire con- 
siderable hardness and strength after they have been exposed to the 
air for several months. This hardness is supposed to be caused by 
the fact that the quarry water contained in the stone holds in solu- 
tion a certain amount of cementing material, which, as the water 
evaporates, 1s deposited between the particles of sand, binding them 
more firmly together and forming a hard outer crust to the stone, 
although the inside remains soft, as at first. On this account the 
stone should be cut soon after it is taken from the quarry, and if any 
carving is to be done it should be done before the stone becomes dry, 
otherwise the hard crust will be broken off and the carving will be 
from the soft interior, and hence its durability much lessened. 


PROTECTION AND PRESERVATION OF STONEWORK. 


180.° There are a great many preparations that have been used for 
preventing the decay of building stones, but all are expensive, and 
none have proved very satisfactory. 

Paint.—The substance most generally used for preserving stone- 
work is lead and oil paint. This is effectual for a time, but the paint 
is destroyed by the atmospheric influences, and must be renewed 


BUILDING STONES. 149 


every three or four years. The paint also spoils the beauty of the 
stone. | . 

The White House at Washington is built of a porous red sand- 
stone, which has been painted white for many years. 

Ozi/.—Boiled linseed oil is sometimes used on stonework, but it 
always discolors a light-colored stone, and renders a dark-colored one 
still darker. “The oil is applied as follows: The surface of the 
stone is washed clean, and, after drying, is painted with one or more 
coats of boiled linseed oil, and finally with a weak solution of 
ammonia in warm water. ‘This renders the tint more uniform. This 
method has been tried on several houses in New York City, and the 
waterproof coating thus produced found to last some four or five 


years, when it must be renewed. The preparation used in coating 


the Egyptian obelisk in Central Park is said to have consisted of par- 


‘affine containing creosote dissolved in turpentine, the creosote being 
- considered efficacious in preventing organic growth upon the stone. 
The melting point of the compound is about 140° F. In applying, 


the surface to be coated is first heated by means of especially 
designed lamps and charcoal stoves, and the melted compound 
applied with a brush. On cooling it is absorbed to a depth depend- 
ent upon the degree of penetration of the heat. In the case of the 
obelisk about } inch.” * | 

A soap and ae solution has also been used for rendering stone 
waterproof, with moderate success. 

Ransome’s Process —This consists in applying a solution of silicate 
of soda or potash (water glass) to the surface of the stone, after it 
has been cleaned, with a whitewash brush until the surface of the 
stone has become saturated. After the stone has become dry a solu- 
tion of chloride of calcium is applied freely so as to be absorbed 
with the silicate into the structure of the stone. The two solutions 
produce by double decomposition an insoluble silicate of lime, which 
fills the pores of the stone and binds its particles together, thus 
increasing both its strength and weathering qualities. This process 
has been used to a considerable extent in England, and is perhaps 
the most successful of all applications. The process of applying the 
solutions is more fully described in ‘“‘ Notes on Building Construc- 


pao, a harte Lilien, 78. 





**‘* Stones for Building and Decoration,” pp. 399-400. 


CHAPTER VI. 
CUT STONEWORK, 


181. To properly lay out, detail and specify the stonework in a 
building, it is necessary to have a thorough knowledge of the differ- 
ent tools and processes employed in cutting and dressing the stone 
and of the different ways in which stone is used for walls, ashlar and 
trimmings. 

The following description of different classes of work, supple- 
mented by critical observation in the stone yard and at the building, 
should give one a good idea of the ordinary methods and practices 
employed in this country : 

Stonework, such as is used in the superstructure of buildings, may 
be divided into three classes: Auddle, Ashlar and Trimmings. 

182. Rubble Work is only used for exterior walls in places 
where suitable stone for cutting cannot be cheaply obtained. There 
are some localities which furnish a cheap, durable stone that cannot 





Fig. 60 —Rubbie, Undressed, Laid at Random. 


be easily cut, such as the conglomerates and slate stones. These 
stones generally split so as to give one good face, and may be used 
with good effect for walls, with cut stone or brick trimmings. 

Fig. 60 shows the usual method of building a rubble wall above 
ground. After the wall is up the joints are generally filled flush with 


CUT STONEWORK. I5I 


, 


mortar of the same color as the stone, and a raised false joint of red 
or white mortar stuck on, to imitate ashlar. Such work should be 
specified to be laid with beds and joints undressed, projections 
knocked off and laid at random, interstices to be filled with spalls 
and mortar. If a better class of work is desired, the joints.and beds 
should be specified to be hammer-dressed. 





Fig. 61.—Random Rubble with Hammer-dressed Joints and no Spalls on Face. 


Fig. 61 shows a kind of rubble work sometimes used for buildings, 
which is quite effective for suburban architecture. It should be 
specified to have hammer-dressed joints, not exceeding $ or # of an 
inch, and no spalls on face. This is 
generally expensive work. 

Fig. 62 shows a rubble wall with 
brick quoins and jambs. 


Occasionally small boulders or field 
stone are used for the walls of rustic 
buildings. In such case the wall 
should be quite thick, with a backing 
of split stone, to hold the boulders, 
and the exact manner in which the 
wall is to be built should be specified. 
There are several kinds of rubble 
used in engineering work, but the 
above are about the only styles used in buildings. 

183. Ashlar.—The outside facing of a wall, when of cut stone, is 
called ashlar, without regard to the way in which the stone is finished. 
Ashlar is generally laid either in continuous courses, as in Figs. 63 
and 64, or in broken courses, as in Fig. 68; or without any continu- 
ous horizontal joints, as in Figs. 65 and 66, which represent droken 
ashlar. Coursed work is always the cheapest when stones of a given 





152 | BUILDING. CONSTROCLION, 


size can be readily quarried, as is usually the case with sand and 
limestones. The cheapest ashlar for most stones is that which is cut 
into 12-inch courses, with the length of the stones-varying from 18 to 


Fig. 63.—Coursed Ashlar. 


24 inches. When the stones are cut 30 inches to 3 feet in length, 
and with the end joints plumb over each other, as in Fig. 63, the cost 
is considerably increased, and if this kind of work is desired it should 


be particularly specified. 


Fig. 64.—Coursed Ashlar. 


Fig. 63 is regular coursed ashlar, each course — inches in height, 
and with plumb bond. When the courses of stone are of different 
heights it is called irregular coursed ashlar. 


CUT STONEWORK. 153 


A form of ashlar now much used is that shown in Fig. 64, in which 
a wide and narrow course alternate with each other. Six and 14 
inches make good heights for the courses. 





Fig. 65.—Broken Ashlar (Six Sizes). 


Fig. 69 shows regular coursed ashlar, with rustic quoins and 
plinth, which is much used in Europe. 
184. Broken Ashlar.—When stones of uniform size cannot be 





Fig. 66.—Broken Ashlar (Three Sizes). 


cheaply quarried the stone may be used to better advantage in 
broken ashlar, but it takes longer to build it, and, as a rule, broken 
ashlar costs considerably more than ccursed eshlar. This style of 


154 BUILDING CON STUCGCLLOL. 


work is generally considered the most pleasing, and, when done with 
care, makes a very handsome wall, as shown by the half-tone illustra- 
tion, Fig. 67. It is generally only used for rock-face work. To have 





Fig. 67.—Broken Ashlar. 


the best appearance no horizontal joint should be more than 4 feet 
long, and several sizes of stone should be used. Broken ashlar can 
be more quickly laid, and at less expense, if the stone is cut to cer- 
tain heights in the yard, so that only one end joint need be cut at 


the building. 





Fig. 68.—Random Coursed Ashlar. 


Fig. 65 is made up of stones cut 4, 6, 8, 10, 12 and 14 inches in 
height, while in Fig. 66 only three sizes of stones have been used. 
Fig. 65 would probably be the more pleasing of the two if executed. 


CUT STONEWORK. 158 


In specifying broken ashlar the height of the stone to be used should 
be specified. Broken ashlar is sometimes arranged in courses from 
18 to 24 inches high, as in Fig. 68, when it is called random coursed 
ashlar. It looks very well in piers. 

185. Quoins and Jambs.—The stones at the corner of a build- 
ing are called the quoins, and these are often emphasized, as in 
Figs. 61 and 69. They should always be equal in size to the largest 
of the stones used in the wall. The stones at the side of a door or 
window opening are called jambs. Fig. 70 represents cut stone win- 
dow jambs in a rubble wall. A portion of the jamb stones should 
extend through the wall to give a good bond. 





In rubble walls the quoins and jambs are often built of brick, as 
shown in Fig. 62. 

All ashlar work should have the bed joints perfectly straight and 
horizontal, and the vertical joints perfectly plumb, or the appearance 
will be greatly marred. 

Trimmings.—This term is generally used to denote all mouldings, 
caps, sills and other stonework, except ashlar. The trimmings may 
be pitched off on their face, but all washes, soffits and jambs should 
be cut or rubbed. 


STONECUTTING AND FINISHING. 


186. That the architect may specify correctly the way in which he 
wishes the stone finished in his buildings, it is necessary that he be 
familiar with the tools used in cutting, and the technical names 
applied to different kinds of finish. 

Stonecutting Tools.—There are several kinds of hammers 
used by masons in dressing rubble, and also a variety of tools used in 
quarrying, but as they are not used in working the finished stone they 
will not be described. 


156 BUILDING CONSTRUCTION. 


Lhe Axe or Pean Hammer, Fig. 71, has two cutting edges. It is 
used for making drafts or margin lines around the edge of the stones, 
and for reducing the faces to a level. It is used after the »noint on 
granite and other hard stones. 





Fig. 70, ; Fig. 71.—Axe or Pean Hammer. 


Lhe Tooth Axe, Fig. 72, has its cutting edges divided into teeth, 
the number of which varies with the kind of work required. It is 
used for reducing the face of sandstones to a level, ready for the 
crandall or tool. It is not used on granites and hard stones. 





Fig. 72.—Tooth Axe. 


The. Bush Hammer, Fig. 73, is a square hammer, with its ends 
(from 2 to 4 inches square) cut into a number of pyramidal points. 
It is used for finishing the surface of sand and limestones, after the 
face of the stone has been brought nearly to its place. 

The Crandall, Fig. 74, is a malleable iron bar about 2 feet long, 
slightly flattened at one end, through which isa slot ~ of an inch 
wide and 3 inches long. Threugh this slot are passed ten double- 


CUT STONEWORK. 157 


headed points of 41-inch square steel, about 9 inches long, which are 
held in place by a key. Only one end of the crandall is used, and 
as the points become dull they can be taken out and sharpened or 





Fig. 73,—Bush Hammer. 


the ends reversed. The instrument is used for finishing sandstone 
after the surface has been prepared by the tooth axe or chisel. 

The Patent Hammer, Fig. 75; sometimes called bush hammer, is 
made of four, six, eight or ten thin blades of steel, ground to an edge 
and bolted together so as to form a single piece. It is used for fin- 





Fig. 74.—Crandall. Fig. 75,—Patent Hammer. 


ishing granite and hard limestones, the fineness of the finish being 
regulated by the number of blades used. 

The Point.—F¥ig. 76, No. 4, has a sharp point, and is used in 
breaking off the rough surface of the stone and reducing it to a plane, 


158 BOLLDINGTCOMNS GeO On Tai: 


ready for the axe, hammer or tool. It is also used to give a rough 
finish to stone for droach work and also for picked work. No. 1, 
Fig. 76, represents the ¢ooth chisel, used only on soft stones; No 2a 
drove, about 2 or 3 inches wide; Nos. 3, 7 and 8 different rorms of 


I 2 3 Ai a es 6 7 8 
Fig. 76. ; 


chisels used on soft stone. No. 5 is a Zool, usually from 34 to 4} 
inches wide, used for finishing sandstone, and No. 6 is a pitching 
chisel, used as in Fig. 77. 

187. Different Kinds of Finish.—2ock-face or pitch-faced 
work is shown in Fig. 77, the face of the stone being left rough as it 





Fig. 77.—Rock-face or Pitch-face. Fig. 78.—Rock-face with Draft Line. 


came from the quarry, with the joints or edges “‘pitched off” to a 
line as shown. ‘The amount of projection of the centre of the stone 
beyond the plane of the joints should be specified. The ashlar shown 
in Fig. 67 is “ rock-face.” 

Rock-face with margin lines is the next step toward finishing a 
stone, and is shown in Fig. 78. The margin (often called draft line) 


CUT STONEWORK. 159 


is cut with a tool chisel in soft stones and with an axe in granite. 
Sometimes only the angle of the quoins has a draft line, as in Fig. 79, 
when it is called “angle draft.” Rock-face ashlar is naturally 
cheaper than any kind of dressed 
ashlar, particularly in granite. 

Broached Work.—The surface 
of the stone is dressed off to a 
level surface, with continuous 
grooves made in it by the point. 
Fig. 80 shows a stone with margin 
or draft lines and broach centre. 

Pointed Work (Figs. 81 and 82). 
—When it is desired to dress the 
face of a stone so that it shall not 
project more than } to } inch, and 
where a smooth finish is not 
required, as in basement piers, etc., 
the rock-face is taken off with a 
point and the surface is rough or fine pointed, according as the point 
is used over every inch or half inch of the stone. The point is used 
more for dressing hard stones than soft stones. 

Tooth-chiseled.—The cheapest method of dressing soft stones is by 
the tooth chisel, which gives a surface very much like pointed work, 
only generally not as regular. 








Fig. 79.—Rock-face with Angle Draft. 





| 


— 


Fig. 80.—Broached with Tooled Margin. Fig. 81.—Rough Pointed. 





Tooled work is done with a flat chisel from 3} to 44 inches wide, 
and the lines are continued clear across the width of the piece, as 
shown in Fig. 83. When well done it makes a very pretty finish for 
sandstone and limestone, and especially for moulded work. 

Drove work is much like tooled work, but done with a chisel about 
24 inches wide and in rows lengthways of the piece, as shown in 
Fig. 84. Drove work does not take quite as much time as tooled 
work, and hence is cheaper, but it does not look as well. 


160 BUILDING CONS TROCTION, 


Bush-hammered.—This finish is made by pounding the surface of 
the stone with a bush hammer, leaving it full of points, as in Fig. 87. 
It makes a very attractive finish for the harder kinds of sand and 
limestones, but ought not to be used on soft stones. 

Crandalled Work (Fig. 85).—The face of the stone is dressed all 
over with the crandall, which gives it a fine pebbly appearance when 
thoroughly done. It makes a sparkling surface for red sandstones, 


Hi 
| 


Fig. 82.—Fine Pointed. Fig. 83.—Tooled. 





and is used more than any other finish in Massachusetts for sand- 
stones. ‘The crandall is not used on granite and other hard stones. 
Rubbed.—One of the handsomest methods of finishing sand and 
limestones is to rub their surfaces until they are perfectly smooth, 
either by hand, using a smooth piece of soft stone with water and 
sand for rubbing, or by laying the stone on a revolving bed called a 
rubbing bed. When the stone is first sawed into slabs rubbing is 






TUT TTTT 


NU 
MMUTUEAUUUUATAUUEAUAUHUOQ HA 


Fig. 84.—Drove Work. Fig. 85.—Crandalled. 





very easily and cheaply done, so that rubbed sandstone ashlar is 
often as cheap as rock-face work in yards where steam saws are used. 
The saws leave the stone comparatively smooth and suitable for the 
top of copings and unexposed places. Granites, marbles and many 
limestones, when rubbed long enough, take a high polish. 

Picked Work.—In this work the face of the stone is first leveled 
off with the point and then picked all over as though a woodpecker 


COLSTON EMWORSE, 161 


had picked it. Broken ashlar finished in this way has a very pretty 
effect, but is quite expensive. 

Patent-hammered or Bush-hammered (Fig. 86).—When it is desired 
to give a finished surface to granite and the hard limestones they are 
first dressed to a rough surface with the point and then to a medium 
surface with the same tool, and finally finished with the patent ham- 
mer. The fineness of the finish is determined by the number of 


















































Fig. 86.—Patent-hammered. Fig. 87.—Bush hammered. 


99 6¢ 


blades in the hammer, and the work is said to be “‘six-cut, 


” 


eight- 
or “ten-cut,” according as six, eight or ten blades are used. 
Government work is generally ten-cut. Eight-cut 1s mostly used for 
average work, aid for steps and door sills six-cut is sufficiently fine. 
The architect should always specify the number of blades to be used 
when the work is to be finished with a patent hammer. The same 
finish may be obtained with the axe, but it requires much more time. 


cut 








— Ore 8.84 i 
O OOOOX A AK / 
EUAN 
Fig. 88.—Vermiculated. Fig. 89.—Fish Scale. 


Vermiculated Work (Fig. 88).—Stones worked so as to have the 
appearance of having been worked by worms. It is generally con- 
fined to quoins and base courses. : 

Rusticated Work.—This term is now generally used to denote sunk 
or beveled joints, as in Figs. 69 and go, although it originally referred 
to work honeycombed all over on the face to give a rough effect, as 
shown in Fig. 69. 


162 BUILDING{GONSTRUCTION. 


Fish Scale or Hammered Brass (Fig. 89).—Work made to imitate 
hammered brass, and done with a tool with rounded corners. 

Vermiculated and fish scale work are seldom seen in this country. 

188. Laying Out.—lIf the cost of the stonework must be con- 
sidered, the architect should ascertain from some reliable local stone 
dealer the most economical size for the kind of stone he intends to 
use, and lay out his work accordingly. 

Trimmings.—If the stonework consists merely of trimmings for 
a brick building, the architect or his draughtsman must first ascertain 
the exact measurement of the bricks as laid in the wall, and the stone 
should be figured so as to exactly fit in with the brickwork, otherwise 





Fig. 90.—Rusticated Joints. 


the bricks will have to be split where théy come against the stone, 
thereby greatly marring the looks of the building. Bond stones and 
belt courses built into a pier must conform exactly to the size of the 
pier. As it 1s seldom that the bricks from any two yards are of 
exactly the same size, the exact size of the bricks that are to be used 
must be taken, as even a variation of + inch often makes bad work. 
189. Drip and Wash.—Projecting cornices, belt courses and other 
trimmings should have sufficient depth that they will dalance on the 
wall, and all projecting stones should have a df as near the top of 
the stone as possible, to prevent the water from dripping over the rest 
of the cornice and down on the wall. Thus inacornice such as 
shown in Fig. 91 the stone should be cut at a sharp angle at 4, so 
that some of the water may drop off, and there should be a regular 
drip at #&, that the water may not run down onthe wall. Itisa 


CUT STONEWORK. 163 


good idea tc cut a drip in all window sills, as shown in Fig. 92. In 
the summer dust always lodges on a sill or projecting ledge, and when 
it rains the water washes the dust, which often contains cinders, over 
the face of the stonework and down on the wall, causing both to 
become badly streaked and often unsightly. 

The architect will find that if he is careful to provide drips on all 
mouldings and sills his buildings will remain bright and clean for a 


Yy 


NN 


Fig. 92. 





much longer time than would otherwise be the case. It is even bet- 
ter to change the profile of the moulding, if necessary, to provide the 
drip, as the most beautiful moulding looks unsightly when streaked 
and stained with dirty water. 

Washes.—The top of all cornices, pelt courses, capitals, etc., should 
be cut so as to pitch outward from the wall line, as shown in Fig. gt. 


Uz, mn 


Fig. 93.—Top of Belt Course. 


If the top is left level, the rain water falling upon it will, in time, dis- 
integrate the mortar in the joint above and finally penetrate into the 
wall. Surfaces beveled in this way are called washes. 

When the face of a wall is broken with pilasters, or the windows 
are recessed, the wash on the belt courses should be cut to fit the 
plan of the wall above, as shown in Fig. 93. 


164 BOUILDING CONSTRUCTION. 


190. Relieving and Supporting Lintels.—[A lintel is the 
stone which covers a door or window opening, and which, therefore, 
acts asa beam. ‘They are often designated by stonecutters by the 





Fig. 94. 


term “cap.’”’] When it is necessary to use rather a long lintel in a 
stone wall the ashlar above the lintel may be arranged so as to relieve 
the lintel of some of the weight, as shown in Fig. 94. If the wall 
above the lintel is of brick a relieving arch may be turned, but this 
generally detracts from the appearance of the 
building, and the best way to strengthen the 
lintel, when the length does not exceed 6 feet, 
is to let it rest on a steel angle bar the full 
length of the cap, as shown in Fig. 95. When 
the width of the opening is more than 6 feet 
the lintel should be supported by steel beams, 
as shown in Figs. 96 and 97. A single beam, 
as in Fig. 96, may be used where only the 
weight of the lintel and its load is to be sup- 
ported, and two or more beams where the 
whole thickness of the wall and also the floor 
joist must be supported. 


When the lintel is the full thickness of the 

wall, and any steel support is undesirable, the ~ 

strength of the lintel may be increased, if of a stratified stone, by cut- 

ting the stone so that the layers will be on edge, like a number of 

planks, placed side by side. The ancient Greeks and Romans often 
cut their lintels in this way, and apparently for this reason. 





Fig. 95 


CUT STONEWORK. 165 


In placing windows in a brick or stone wall the aesigner should 
be careful to arrange them so that they will not come under a pier. 
This is not apt to happen in the front of a building, but it sometimes 
happens on a side or rear wall, where the windows are placed to suit 
the interior arrangement and without regard to the external effect. 

If a door or window must be placed under a pier or high wall steel 
beams should be used to support the wali above and also the lintel. 
Many broken lintels are evidence of a too frequent neglect of this 
precaution. 

Another point that should be carefully considered in laying out the 
stonework is building the ends of caps and sills into piers. If the 





Fig. 96. Fig. 97.—-3¢-inch Steel Plate Riveted to Beams. 


pier extends through several stories the joints will all be slightly com- 
pressed and the masonry will settle some, and if the ends of the caps 
and sills of the adjoining windows are solidly built into the piers they 
are very apt to be broken as the pier settles. 

The best arrangement is to keep the caps and sills back from the 
face of the pier, and either build pilasters against the pier to receive 
the caps and sills, as shown at 4, Fig. 98, or else build the ends of 
the stones into the pier in such a way that they can give a little. 
When the cap is back from the face of the pier this can easily be 
done. 

Lintels should have a bearing at each end of from 4 to 6 inches, 
according to the width of the opening. It is better not to build the 
ends into the wall more than is necessary to give a sufficient bearing. 

Composite Lintels—Very often it is desired to place a stone lintel 
over a store window to or 12 feet wide. To procure such a lintel in 
one piece is, in many places, impracticable. and it is therefore 


166 BUILDING CONSTRUCTION. 


necessary to build the lintel up in pieces. When such is the case at 
least three stones should be used, and the end joints should be cut 
as shown in Fig. 99. Cutting the stones in this way binds them 
together better, and also gives the appearance of being self-support- 
ing. A greater number of stones, say five or seven, may be used if 
preferred, but the joints should be cut in the same way. Such lin- 





Fig. 98. 


tels should always be supported by steel beams, either as shown in 
Fig. 96 or Fig. 97. 

191. Sills.—A ‘‘sill’’ is the piece of stone which forms the bot- 
tom of a window opening in a stone or brick wall. Doorsteps or 
thresholds are also often called “sills.” 

A slip sill is a sill that is just the width of the opening, and is not 
built into the wall. 

Lug sills are those which have /éat ends, built into the wall, as 
shown in Fig. roo. 


GOT SLONEAW ORE. 167 


All sills should be cut with a wash of at least $ inch to 5 inches in 
depth, and if the ends are to be built into the wall they should be 
cut as shown in Fig. roo. In some parts of the country the sills are 
cut with a straight beveled surface the full length of the stone, and 
where they are built into the wall the bricks are cut to fit the stone. 
This is not a good method, as the water running down the jamb and 


striking the sill is apt to enter the joint between the brick and stone, 
and the slanting surface also offers an insecure bearing for the brick. 

Slip sills are cheaper than lug sills, but they do not look as well, 
and there is also danger of the mortar in the end joint being in time 
washed out. 

Slip sills, however, are not likely to be broken by any settlement in 
the brickwork, and for this reason many architects prefer to use them 
for the lower openings in heavy buildings and 
also for very wide openings. 

Lug sills should not be built into the jambs 
more than 4 inches, and should only be 
edded at the ends when setting. 

192. Arches.—Stone arches are very fre- 
quently used both in stone, and brick build- 
ings. They may be built in a great variety of 
styles, and with either circular, elliptical or 
pointed soffits. The method of calculating 
the stability of a stone arch is the same as for a brick arch, but a 
stone arch being constructed in larger pieces, the mortar in the joints 
adds but very little, if any, to the stability of the arch, and a stone 
arch of the same size as a brick arch is rather more liable to settle or 
crack than the brick arch, and should be constructed with greater 
care. The method of calculating the stability of arches is given in 
Chapter VIII. of the Architects’ and But'ders’ Pocket Book. In 
block stone arches each block, or “voussoir,’’ should always be cut 
wedge-shape and exactly fitted to the place it is to occupy in the 


Fig. 99. 


or 





Fig. 100. 


168 BUILDING CONSTAROCTION. 


arch. The joints between the voussoirs should be of equal width the 
entire depth and thickness of the arch, that the bearing may be uni- 
form over the entire surface. The thickness of the joint will depend 
somewhat upon the character of the stonework. In finely dressed 
work 5°; of an inch is the usual thickness, while in rock-face work it 
is seldom made less than 3 of an inch. One-fourth of an inch, how- 
ever, is all that should be allowed in first-class work. 


The joints should also radiate from the centre from which the 
intrados is struck, or, in the case of an elliptical arch, they should be 
at right angles to a tangent drawn to the intrados at that point. See 
Fig. 106, Section 198. 

The back of the arch may either be concentric with the intrados, 
or the ring may be deeper in the centre than at the sides. 





Fig. zor. 


The most common stone arch is that shown in Fig. 101, the arch 
ring being of equal depth and the voussoirs all of the same size, and 
rock-face, with pitched joints. Occasionally the voussoirs are cut 
with a narrow margin draft, as shown at 2. When the springing 
line of an arch is below the centre, as shown in Fig. 101, the arch is 
said to be “‘stilted,”’ the distance S being called the “stilt.” Stilted 
arches are very common in Romanesque architecture. 


A semicircular arch is one of the best shapes for supporting a wall. 
It must, however, have sufficient abutment, and the depth of the arch 
ring, or the distance from the intrados to the extrados, in feet, should 
be at least equal to o.2-+ 4/ radius + half span 

4 

Arches used in connection .with coursed ashlar, especially in 
Renaissance buildings, often have the voussoirs cut to the shapes 
shown in Figs. 102 and 103. 


~ 


CUT STONEWORK. 169 


Such arches are of course more expensive than arches with the 
intrados and extrados concentric, as there is more waste to the stone 
and more patterns are required. They have a more pleasing appear- 
ance, however, and are also stronger. Voussoirs of the shape shown 
in Fig. 103 must be cut with extreme accuracy. 


In dividing the arch into voussoirs it should be remembered that, 
as a rule, narrow voussoirs are more economical of material, but more 
expensive in point of labor. 


In most arches the width of the voussoirs at the bottom is about 
three-eighths of the width of the ring, although they may vary from 
one-fourth to one-half. 

Very often two voussoirs are cut from one stone, with a false joint 
cut in the centre. This is done generally for economy, although in 





Fig. 102. Fig. 103. 


some cases it may add to the stability of the arch. Generally the 
arch is divided into an uneven number of voussoirs, so as to give a 
keystone, the voussoirs being laid from each side and the keystone 
fitted exactly after the other stones are set. Except that it is more 
convenient for the masons there appears to be no necessity of having 
a keystone, and the author has been informed that Sir Gilbert 
Scott always used an even number of voussoirs, believing that 
thereby the danger of the voussoirs cracking was decreased. 


193. Label Mouldings.—In nearly all styles of architecture the 
better class of buildings have the arch ring moulded. In Gothic and 
Romanesque work a projecting moulding called a “label mould”’ is 
generally placed at the back of the arch. When not very large it 
may be cut on the voussoirs, but usually it is made a separate course 
of stone, as shown in Fig. 104. When this is the case the depth of 
the arch ring without the label mould should be sufficient for stability, 


170 BUILDING CON SL RU GL OV: 


The label mould may be cut in pieces of the same length as the vous- 
soirs, or the joints may be made independent of those in the arch. 


194. Built-up Arches.—Large arches, especially those which 
show on both sides of the wall, are often, for the sake of economy, 
built of several courses of stone, jointed so as to give the appearance 
of solid voussoirs. Fig. 104 shows the. manner in which many of the 
large arches designed by the late H. H. Richardson were constructed. 
Every alternate pair of voussoirs should be tied together by galva- 
nized iron clamps. 





195. Backing of Stone Arches.—The arches generally seen 
in the fronts of buildings are usually only about 6 inches thick, and 
are backed with brick arches. The brick arch should be of the same 
shape as the stone arch, and the bricks should be laid in cement 
mortar, so that there may be no settlement in the joints. The back- 
ing should be well tied to the stonework by galvanized iron clamps. 


196. Relieving Beams Over Arches.—Very often arches are 
used for effect in places where sufficient abutments cannot be pro- 
vided to resist the thrust of the arch. In such cases one or more 
steel beams should be placed in the wall just above the arch, with 
the ends resting over the vertical supports and an empty joint left 
beneath the centre of the beams. The wail above can then be built 
on these beams, leaving the arches with only their own weight to sup- 
port. The additional weight which the beams carry to the abut- 
ments also greatly increases their resistance to a horizontal thrust. 
The beams should also be provided with anchors at their ends, with 
long vertical rods passing through them, to tie the wall together. 


GOI SLONEWORK. Le 


Wherever segmental arches are used it is always a safe precaution 
to place steel rods back of them to take up the thrust of the arch 
while the mortar in the abutments is green. 


197. Support for Spandrels.—Wherever arches are used in 
groups care must be exercised in laying out the springing stones to 
give a level support for the spandrels. Thus where two arches come 
‘together, as at 4, Fig. 105, if the first voussoir is cut to the shape of 
the arch on the back a small wedge-shaped piece of stone would be 
required to fill the space between the first pair of voussoirs. The 
weight of the wall above coming on this wedge might be sufficient to 
force the voussoirs in and seriously mar the appearance of the arch, 
as well as causing cracks in the ashlar above. This danger may be 


one 
B piece. 





Fig. 105. 


overcome by cutting the lower stone, a a, in one piece for both arches 
and extending the voussoir, 4, to a vertical joint over the centre of the 
pier. This gives a level bearing for the lower stone in the spandrel 
and effectually prevents any pushing in of the voussoirs. 

Another case very similar to this often occurs where the back of 
an arch comes almost to the corner of the wall or projection, as 
shown at 4. If the distance between the back of the arch and the 
angle of the wall is less than 8 inches the lower voussoir should be cut 
the full width of the pier, as shown in the illustration. 


198. Elliptical Arches.—Arches built either in the form of an 
ellipse or oval, or pointed at the centre and elliptical at the springing, 
are often used for architectural effect in buildings, although very 
seldom in engineering works. Such arches are very liable to either 
open at the centre and “kick up” at the haunches, or to fail by the 
centre voussoirs being forced down. An elliptical arch, especially 
if very flat, is undesirable for spans of over 8 feet, and should never 


172 BUILDING CONSTAOCLION,. 


be used without ample abutments unless beams are placed above the 
arch as described in Section 196. 

The joints of an elliptical arch should be exactly normal (at 
right angles) to the curve of the soffit. If the line of the soffit 
is not a true ellipse, but is made up of circular arcs of different 
radii, the joints in each portion of the arch should radiate from 
the corresponding centre. Fig. 106 shows an easy method for 
laying out the joints where the curve of the soffit is a true 
ellipse. set. 4775, 27s, 77. etc, be points pons the reilipse strom 
which it is desired to draw the joints. Draw tangents to the ellipse 
at the points 4 and Z intersecting at C. Draw the lines 44 and 
OC. Draw lines from 1/,, M72, M73, etc., perpendicular to OA and 
intersecting OC at Z,, L., £3, etc. From these points draw lines 
perpendicular to 4, intersecting O4 at 7V,, Vz, V3, etc. Lines 
drawn through VV, 47,, VM, etc., will then be normal to the curve 
and give the joints desired. 






o 







t 

| 

ea 

! f 

4 4 

ad 

Aer ha ¥) a7 (3 

| RS At / ryt 

a 4 wae Pa y bythe oe 

rie A Od Al Ly ye 
N7 Ne Ns Na N3 Ne No A 


Fig. 106, 


199. Flat Arches.—Shallow flat arches of stone, although some- 
times pleasing to the eye, are very objectionable constructionally. If 
a flat arch must be used, to be self-supporting it should be of such 
height that a segmental arch of proper size can be drawn on its face, 
as indicated by the dotted lines in Fig. 107. Even then it is desir. 
able to drop the keystone about 1 inch below the soffit line, so as te 
wedge the voussoirs tightly together. An arch such as is shown in 
Fig. 107 might be safely used for a span of 5 feet, but with great 
caution for larger spans. The strength of such an arch may be 
increased by “joggled”’ joints, that is, notching one stone into the 
other, as shown by the dotted lines at a. Such joints, however, are 
quite expensive. 


CUT STONEWORK. 173 


Very shallow flat arches, such as is shown in Fig. #y «sould be 
cut out of one piece of stone, so as to be in reality a ¥ntel with false 
joints cut on its face. The ends of the lintel should have a bearing 
on the wall of 6 inches, as shown 
bythe dotted) lines .the face 
being cut away for about 2 
inches in depth and veneered 
with brick. If this method is 
too expensive the lintel might be 
cut in three pieces and sup- 
ported by a heavy angle bar, as 
shown in Fig. 95. 

Very long lintels are often 
made in the form of a flat arch (see Section 190), but are, or should 
be, always supported by steel beams or bars. 

Rubble Arches.—Arches are sometimes built of rubble stones. 
The stones should be long and narrow and roughly dressed to a 
wedge shape. They should be built in cement mortar, as they 
depend largely upon the strength of the mortar for their stability. 





Fig. 107. 





Fig. 108. 


200. Centres.—All arches, whether of stone or brick, should be 
built on wooden centres made to exactly fit the curve of the arch and 
carefully set. The centres should have ample strength to support 
the weight of the arch and much of the wall above, as it is unde- 
sirable to put any weight on the arch until the mortar in the joints 
has become hard. Centres are usually made with two ribs cut out of 
plank and securely spiked together, and the bearing surface formed 
of cross pieces about 1x2 inches in size nailed to the top of the ribs, 
as shown in Fig. 109. The ribs forming the supports for the cross 
pieces should be placed under each edge of the arch, and if the | 
depth of the arch exceeds 12 inches three ribs should be used. The 
centre should be supported on wooden posts resting on blocks set on 
the sill or some sufficient support below. It should not be removed 
until the mortar in the arch joints has had ample time to set. 


174 BUILDING CONSTROUCTION. 


Centres for spans of considerable extent are framed together with 
heavier timbers and in-a variety of ways. The general method is 
shown by Fig. 110, which represents a centre for a 10-foot span. 
The framework, indicated by the straight pieces, is made of 6x6 or 
4x8 timbers, and to these are spiked pieces of plank cut to the out- 
line of the arch. The cross pieces are then nailed to the top edge of 
the planks, as in Fig. 10g. Such a centre should have a support 
under the middle as well as at the sides. As the centres are only 





Fig. 109. 


required for temporary use, architects generally allow the carpenter 
to construct them as he deems best, but the superintendent should 
satisfy himself that they are of ample strength and well supported 
before the masons commence building the arch. 


MISCELLANEOUS TRIMMINGS. 


201. Columns not exceeding 8 feet in height usually have the 
shaft cut in one piece and the caps and bases in separate pieces. For 
columns of greater height it is generally necessary to build the shaft 
of several pieces. The joints between the cap and base and the 
shaft, and between the different stones of the shaft, should be dressed 
perfectly true to the axis of the column and to a true plane, so that 


CUT STONEWORK. © 175 


the pressure will be evenly distributed over the whole area of the 
joint. Nothing but cement mortar should be used in these joints, 
and the outer edge of the joint for 3 of an inch from the face should 
be left empty to prevent the outer edges chipping off. 





Fig. 110. 


If the column is built against a wall, the pieces from which the 
cap and base are cut should either extend into the wall or be secured 
by galvanized iron clamps. 

Lntablatures spanning porch openings, etc., may either be cut from 
one piece of stone, or, if of considerable height, of several pieces. 

Fig. 111 shows a common method of 
building up an entablature, the corona and 
facia being in still another course above 
those shown. When jointed as in the fig- 
ure the bottom joint should not be filled 
with mortar except at the ends. 








te. POLS NPE BLE o> BST 
4 Fd * DPV eZ Hanus - 
De oO NNT ale 
ree aan a 2 or) ey.) 
Nive ha SS 
Chas a 
ed YS 








The various stones composing the cornice 
and entablature should be well tied together 
with iron clamps, and especially at all 
external corners. It is also a good idea to 
tie the cornices of porches to the building 
by long rods built inside the mason work 
to prevent the porch from “pulling away” from the wall. 

202. Copings.—All walls not covered by the roof should be 
capped by a wide stone called the coping. Horizontal copings should 
be weathered on top and have a drip at the bottom edge, as shown at 
C, Fig. 112. The width of the coping should be about 3 inches 
greater than that of the wall. 


176 BUILDING CONSTAUCCTION. 


Gable copings do not require a weathering on top, but they should 
project about 14 inches from the face of the wall, and should have a 
sharp outer edge, so that the water will rot run in against the wall. 
As the weight of the coping has a tendency to cause it to slide on the 
wall, it should be well anchored to the wall, either by bonding some 
of the stones into the wall, or by long iron anchors. The bottom 
stone, sometimes called the “‘kneeler,”’ should always be bonded 
well into the wall with a horizontal bed joint, as shown at 4, 
Fig. 112. About once in every 6 feet in height a short piece of cop- 
ing should be cut so as to bond into the wall as at Z. Gable copings 
sometimes have the part which rests on the wall cut in steps, so that 
each stone has a horizontal bearing. This method, however, is very 





Fig. 112. 


expensive, unless the coping is cut in very short pieces, and this is 
objectionable on account of the number of joints required. 

As a rule copings should be in as long stones as possible to avoid 
joints which admit the wet. Horizontal coping stones are often 
clamped together at their ends to prevent their getting out of place 
sideways. 

203. Stone Steps and Stairs.—These should always be built 
of some hard stone, preferably granite, and should have a solid bear- 
ing. Outside steps generally rest on a wall at each end, and if more 
than 6 feet long should have a support at the centre. Each step 
shou!d rest on the back of the one below at least 14 inches. Steps 
to outside entrances should pitch outward about + inch. Steps are 
much more comfortable when cut with a nosing, but owing to the 
increased expense this is only done in costly buildings. 


CUT STONEWORK. 177 


Stone stairs may be built with only one end supported. In Euro- 
pean buildings, and many of our Government buildings, the stairs 
are constructed as shown in Fig. 113, either with or without nosings. 
One end of the steps is solidly built into the wall, and each step is 
supported by the one below, owing to the way in which they are cut. 
The bearing of one step on the other should not be less than that 
shown in the figure. The bottom step must obviously be well sup- 
ported its full length, as it has to sustain nearly the full weight of the 
stairs. The steps are usually cut with a triangular cross section as 
shown, as it is less expensive and reduces the weight of the stairs, 
besides giving a pleasing appearance from below. 

The railing is generally 
LANDING. of iron, doweled into the 
ends of the steps. 

The laying out and 
detailing of other stone 
trimmings will be gov- 
erned by the principles 
above noted. 

204. Ashlar.—Zaying Out.—After the kind and size of ashlar to 
be used has been determined upon the draughtsman should show each 
piece of ashlar on the elevation drawings if coursed ashlar with plumb 
bond is to be used, and stones of particular lengths desired. If there 
are piers on the outside of the building a section drawing should be 
made showing how the stone in the pier is to be bonded with the rest 
of the wall. 

For all public buildings and most office and business blocks it is 
generally best to show ezevy stone on the plans unless broken ashlar 
is to be used, when the labor would be wasted. As a rule, in ordi- 
nary stone dwellings and in fact most stone buildings, either broken 
ashlar is used or coursed ashlar of irregular lengths, in which case it 
is not necessary to indicate the ashlar on the elevation drawings, 
- except to show the height of the courses, if coursed ashlar is used. 
_- When broken ashlar is used only the quoins and jambs need be shown, 
and a small piece of ashlar indicating the kind of work desired, as it 
- would be almost impossible for the mascns to carefully follow a draw- 
ing of broken ashlar. 

Thickness of Ashlar.—Broken ashlar, and coursed ashlar not 
exceeding 12 inches in height, generally varies from 4 to § inches in 
thickness, and averages 6 inches. The different courses should vary 
in thickness, as shown in Fig. 117, it being better to have one course 





Fig. 113. 


178 BOUILDINGACON STO Gid GY. 


4 inches thick and the next 8 inches than to have all 6 inches. No 
ashlar, however, should be less than 4 inches in thickness, even if of 
marble. Ashlar laid in alternating high and low courses, as 6 inches 
and 14 or 20 inches, should be cut so that the low courses will be at 
least 8 inches thick and the high courses 4 inches thick, and each 
stone in the latter courses, when 18 inches or more in height, should 
have at least one iron anchor extending through the wall. 


Fig. 114 shows the form of : 


anchor generally used. The 
high courses, when of sandstone 
or limestone, are generally 
sawed of a uniform thickness. 

Joints.—It is important that 
the surface of each stone shall be “out of wind,” that is, a true 
plane, and square to the bed and end joints. 

The bed joints should be full and square to the face and not 
worked hollow, as in Fig. 115, as with hollow joints the least settle- 
ment in the mortar will throw the whole pressure on to the edge of 
the stone at C, and cause a “spall” or pieces to splinter off, which 
ruins the appearance of the building, and, moreover, causes a ‘sus- 





Fig. rz. 


picion as to its safety. Stonecutters are very apt to work the joints 
hollow and the back of the joint slack, as in Fig. 116, as it requires 






yey 





ALLA, 
LG itiitists: 





Hic 11s: Fig. 116. 


much less labor than to dress the joint evenly, and, unless carefully 
looked after, will cut the stone that way in nearly nine cases out of 
ten. If the back of the joint is left slack and underpinned, as in 
Fig. 116, the stone is then supported only at the front and back, and 
liable to break in the middle, as shown. Of course, in.a wall not 
exceeding 20 feet in height, the danger arising from imperfect joints 
is not as great as in a wall of six or more stories. The higher the 
wall the more carefully should the joints be cut. It is also desirable 
that the joints should not be convex. 


CUT STONEWORK. 179 


For very heavy masonry, as in the basement or first story of tall 
buildings, it is desirable to use rusticated joints (see Fig. go), as with 
such joints there is less chance for the face to spall. 

The thickness of ashlar joints varies from ;3, to } inch. A 4-inch 
joint, when pointed, makes very good-looking work. A 43-inch joint 
is too wide for anything but rock-face ashlar, and nothing over a 
14-inch joint should be used for heavy work. 

205. Lacking.—Both stone and brick are used for the backing of 
ashlar. Brick is more largely used for this purpose than stone, 
because in most cases it is 
the cheapest, and it pos- 
sesses the further advan- 
tage that the plaster may in 
dry climates be applied 
directly to the brick, while 
the stone backing generally 
has to be plugged and 
stripped for lathing. If 
brick is used for backing 
the joints should be made 
as thin as possible, and it is 
deswabpiewst oO. 11s 65:0. € 
cement in the mortar to 
prevent shrinkage in the 
joints. The backing, if of 
brick, should never be less 
than 8 inches in thickness. 
If a hard laminated stone, 
with perfectly flat and par- 
allel beds, can be obtained 
for backing, it makes a 
stronger job than brick, but irregular rubble blocks are not suitable 
for anything but dwelling house walls, unless the walls are made one- 
fourth thicker than with brick backing. The backing, whether of 
brick or stone, should be carried up at the same time with the ashlar, 
and, if of stone, should be built in courses of the same thickness as 
the ashlar, as shown in B, Fig. 117. 

Bonding.—Ashlar not exceeding 12 inches in height i§ usually 
bonded sufficiently to the backing by making the stones of different 
thicknesses, as in Fig. 117, and by having one through stone to every 
Io square feet of wall. 





Fig. 117. 


180 BUILDING CONSTRUCTION. 


Where the ashlar is only about 2 inches or 4 inches thick, as is 
generally the case with marble, and often with sandstones, each piece 
of ashlar should be tied to the backing by an iron clamp, about 4 of 
an inch thick and 1 or 1} inches wide, with the ends turned at right 
angles, as shown in Fig. 114. The anchors should be made of just 
the right length for the longer end to turn up just on the inside of 
the wall. Every stone should have one clamp, and if over 3 feet 
long two clamps should be used. ‘There should also be belt courses 
about every 6 feet, extending 8 inches or more into the wall, to give 
support to the ashlar. 


‘The effective thickness of a wall faced with thin ashlar is only 
equal to the thickness of the backing. When iron clamps are used 
for tying the ashlar they should be either galvanized or dipped into 
hot tar to prevent being destroyed by rust. 


206. Slip Joints.—Where two walls differing considerably in 
height come together, as for instance where the front or side wall of 
a church joins the tower, the two walls should 
not be bonded together, but the low wall should 
TOWER. be “housed”’ into the other, so as to form a con- 
tinuous vertical joint from bottom to top, as 

Coin shown in Fig. 118. | 
Such a joint is called a slip joint. All mason 
work built with lime mortar will settle some- 
what, owing to a slight compression in the joints, 
and this settlement is sometimes sufficient to 
cause a crack where a high and low wall are bonded together. In 
such cases there is also a chance for uneven settlement in the foun- 
dations, even when carefully proportioned. With a slip joint a mod- 

erate settlement may take place without showing on the outside. 


Fig. 118. 


207. Bond Stones and Templates.—The building regula- 
tions of certain cities require that bond stones shall be used in brick 
piers of less than a certain size. When such stones are used they 
should be of some strong variety, and should be cut the full size of 
the pier. It is also very important that the outside and inside bricks 
be brought exactly to the same level to receive the stone, for if the 
stone bears only on the outside bricks the weight will cause them to 
buckle ‘and separate from the pier, while if the weight is borne by 
the centre of the pier it is hable to crack through the middle. 


Bond stones should not be used in a wall in the manner shown in 
Fig. 119, as they give the pressure no chance to spread, but keep con- 


CUT STONEWORK. 18¢ 


_centrating it back on the part of the wall immediately under the bond 


stones, as shown by the short vertical lines. 

Bearing stones used under the ends of beams or girders to distrib- 
ute the weight on the walls are called ¢emp/ates. ‘They should always 
be of a very hard, strong stone, laminated if it can be obtained, and 
the thickness of the stone should be one-third of the narrowest 
dimension of the stone, unless the stone is unnecessarily large, but in 
no case less than 4 inches. It is always better that templates be too 
large rather than too small. 

The area of the templates should be such that the pressure which 
it transmits to the wall below shall not exceed 120 pounds per square 
inch for common brickwork, or 150 pounds 
for common rubble with flat beds. 

It is also a good idea to place a flat stone 
above the end of a wooden girder, so that 
the wall will not rest on the wood, which is 
quite sure to shrink and possibly affect the 
wall. 

208. Setting Stonework.—All stones 
should be set in a full bed of mortar, and 
any stone too large to be easily lifted by 
one man should be set with a derrick. 

In some localities slips of wood are pre- 
pared of the thickness desired for the joints 
and laid on ne top of the stone below, so that when the stone is set 
the mortar squeezes out until the stone rests on the slips of wood. 
After the mortar has set or hardened the slips are withdrawn. The 
bed of mortar should always be kept back an inch or more from the 
edge of the stone. This will prevent the stone bearing just on the 
outer edge, and save raking out the mortar preparatory to pointing. 
In damp places stonework should be set in cement, or lime and 
cement mortar; in dry situations it may be set in lime mortar. 

Most of the granular limestones and marbles, and some sandstones, 
are stained by either Portland or Rosendale cement, and when using 
any of these stones for the first time the architect should ascertain 
their liability to stain. The mortar for bedding the stone can always 
be kept from the face of the stone by exercising a little care, and the 
joints afterward pointed with some material that does not stain. 
Stone masons are often very careless in setting stonework, and do not 
bed the stones evenly, so that when the weight comes upon them 
they crack. 












































182 BUILDING CONSTRUCTION. 


Marble and limestone are sometimes set in a cement made of lime, 
plaster of Paris and marble dust, and called Lafarge cement. When 
such cement is used for setting, and other cements for the backing, 
the back of the stone ashlar should be plastered. with the former 
cement. Window and door sills should only be bedded at their ends 
when set and no mortar put under the middle of the sill, otherwise 
the settlement of the walls will break the sill. 


Protecting.—The carpenter’s specifications should contain a 
clause providing for the boxing of all mouldings, sills and ornamental 
work with rough pine to prevent the stone being Hse during the 
construction of the building. It is said that hem- 

“ock stains the stone, and should therefore never 
‘ye used for this purpose. 

209. Pointing.—As the mortar in the ex- 
posed edges of the joints is especially subject to 
dislodgment through the expansion and con- 
traction of the masonry and the effects of the 
weather, it is customary after the masonry is laid 
to refill the joints to the depth of half an inch or 

more with mortar prepared 
especially for this purpose. 
This operation is called 


pointing 
Y) Pointing is generally done 
as soon as the outside of (2232275! 58% 
Wy, the building is completed, 
unless it should be too late 
in the season, when it 
should be delayed until 
spring. Pointing should never under any circumstances be done in 
freezing weather. It is also not desirable to do it in extremely hot 
weather, as the mortar dries too quickly. 





Fig. 120. 


Portland cement mixed with not more than an equal volume of 
fine sand and such coloring matter as may be required, with just 
enough water to give the compound a mealy consistency, makes the 
most durable mortar for pointing. If the stone is stained by cement, 
Lafarge cement should be used, or a putty made of lime, plaster of 
Paris and white lead. 

Before applying the pointing the joint should be raked out to the 
depth of an inch, brushed clean and well moistened. 


CUT STONEWORK. 183 


The mortar is applied with a small trowel made for the purpose 
and then squeezed in and rubbed smooth with a tool called a jointer 
(Fig. 120) and made for that purpose:  Jointers are made with both 
hollow and concave edges, so as to give a raised or concave joint, as 
shown in Fig. 121. The concave joint is the most durable, although 
the raised joint makes perhaps the handsomest work. 

Cleaning Down.—This consists in washing and scrubbing the 
stonework with muriatic acid and water. Wire brushes are generally 
used for marble work and sometimes for sandstone, but stiff bristle 
brushes usually answer the purpose as well. The stones should be 
scrubbed until all mortar stains and dirt are entirely removed. The 
cleaning down is done in connection with the pointing. 

For cleaning an old front the sand blast, using either steam or 
compressed air, does the work most effectively, as it removes from 
giz to 45 of an inch from the surface of the stone, making it look like 
new. Even carving can be successively treated in this way. | 

210. Strength of Stone Masonry.—Practically the only cases 
in which the strength of stonework need be considered by the archi- 
tect, other than to see that proper construction is provided, are: 
a, the strength of piers; 4, strength of columns ; ¢, strength of lintels. 

Strength of Stone Piers—The following figures may be taken for 
the working strength of stone piers. The figures in the first column 
may be taken for a fair quality of work laid in good lime mortar, 
those in the second column for the best class of work laid in cement: 


ERCrCLOM ban scaaithe GNC y ee seis nes ania b's ew ee 0 heels 5 to 20 tons. 
RR IEL LG metretere Naree Maree tas co Aaietat, s See Sis eons se 3 8 ae ous Oe dae 
MIIUALCCEStONG. -SrINClis|OMlSyee seis e eths coc heist 6 6 oc ne T5:10)20 
DAU tOnesnc Olan wr INCU V1OINtGr.s sais cists cee oes «wwe 10 £0, 20% -*" 
Limestonerashilars=incheyGintss sels ase oo « u,a01 ces «os 20to25 ‘ 
SoPatipe estar peril JOLALS. Ac! va ws) a sic) + 6 5.050 09.8. 508 > 30mEs 


The ashlar to be at least as thick as it is high and well bonded. 

Strength of Columns.—A stone column, free from defects, carefully 
bedded and not exceeding ten diameters in height, should safely 
carry a load equal to one-fifteenth of the breaking load of stone of 
the same kind and quality. Any column loaded with over fifteen 
tons to the square foot should be bedded in Portland cement mortar, 
of not more than 1 to 1, and the mortar should not be allowed to 
come within 1 inch of the edge of the column until after the build- 
ing is done, when the joint may be pointed the same as ashlar. As it 
is difficult to secure a joint which will stand more than forty tons to 
the square foot, that should be the limit of load for a stone column, 


184 BOILDING GONSTRCCLION: 


no matter how strong the stone is, unless extra precautions are taken 
with the joints. The following values may be used for the safe loads 
of columns of the different stones specified, the shaft of the column 
being in one piece: 


Longmeadow (Mass.) red sandstone, best.... 35 tons per square foot. 
Potsdam red sandstones ac, ee oars ten tee eee 40 MY a 
Manitou (Colo.) red sandstone, best... .25 to 30 7 a 
Cyhio San istone. at aes usta aire se eo 25 ‘ - 
Fond du-Lac( Wis. )\sandstoné... a. 24s: 25 ch aS 
Limestone; .Glens-Falls® NAY... Jclle aatye setae 35 a} fe 
Tamestene indiana: oie anya ete a On as 4 4: 
Limestone, strongest varieties... oe ssn 40 ee an 
Marble sIite, Mass ye <> erie Sete .. 40 a 3 
Marbles nutlandonVt 26 etcetera 30 to 35 Es ‘s 
Granite, apy, ool pood qtality. .cwwiss ee st or 40 > 


If the columns are built up of several pieces the joints should not 
exceed 5% of an inch in thickness, and the bed surfaces should be 
perfectly true and square to the axis of the column. 

211. Strength of Lintels—A lintel is nothing more than a stone 
beam, and the same formule apply to stone as to wood, with the 
exception of the quantity representing the strength or “‘modulus of 
rupture” of the material. The following formule give the strength 
of lintels under distributed and concentrated loads, the only cases 
likely to occur in practice: 
2X breadth X square of depth 

span in feet 

Concentrated centre breaking load = one-half the distributed load. 

The breadth and depth should be taken in inches. C is one- 
eighteenth of the average modulus of rupture, and may be taken as 
follows : 

Granite, 100; marble, 120; limestone, 83; sandstone, 70; slate, 
300; bluestone flagging, 150. 

These formule give the breaking strength of the lintel. If the load 
on the lintel consists only of masonry, and is not subject to shocks or 
impact of any kind, the safe load may be taken at one-sixth of the 
breaking load. If there are any unfavorable circumstances the safe 
load should not exceed one-tenth of the breaking load. 

Nearly all laminated stones are stronger, as beams, when set on 
edge, and where the full strength of the stone is required, they may 
with advantage be set in this way and be protected from the weather 
by placing a moulded course above set on its naturai bed. 


Distributed breaking load = DAC, 





CUT STONEWORK. 185 


Floor beams, or any construction carrying a live or moving load, 
should never be supported on a stone lintel. The above formule 
apply to a slab as well as to a lintel, although if the slab has a bear- 
ing on all four sides the strength will be considerably increased. j 

Example.—What is the safe distributed load of a granite lintel, 6 
feet opening, 20 inches high and 8 inches thick ? 

SOs 20" 
an 

One-sixth of this gives 17,777 pounds for the safe distributed load. 

Example [7—What is the safe distributed load for a bluestone 
fing 4 feet clear span, 4 feet wide and 4 inches thick? 
2X 48X 4” X 150 

4 

As the load on a flag would very probably be a live or moving 
load, we will make the safe load only one-tenth of the breaking load, 
or 5,760 pounds. 

212. Measurement of Stonework.—Rough stone from the 
quarry is usually sold under two classifications, 7wb/e and dimension 
stone. Rubble includes the pieces of irregular size most easily 
obtained from the quarry, and suitable for cutting into ashlar 12 
inches or less in height and about 2 feet long. Stone ordered of a 
certain size, or to square over 24 inches each way, and of a particular 
thickness, is called dimension stone. The price of the latter varies 
from two to four times the price of rubble. 

Rubble is generally sold by the perch or car load. Footings and 
flagging are usually sold by the square foot; dimension stone by the 
cubic foot. In Boston granite blocks for foundations are usually 
sold by the ton, and rubble for foundations is often sold that way in 
various localities. | 

In estimating on the cost of stonework put into the building, the 
custom varies with different localities, and even among contractors, 
in the same city. 

Dimension stone footings (that is square stone 2 feet or more in 
width) are usually measured by the square foot. If built of large 
rubble or irregular stones the footings are measured in with the wall, 
allowance being made for the projections.of the footings. 

Rubble work is most often measured by the perch, which consists of 
24% cubic feet in the East and of 16% cubic feet (by custom) in Col- 
orado, and in some localities 22 cubic feet are called a perch. 

If work is let by the perch it should be distinctly stated in the con- 
tract the number of cubic feet that are to constitute a perch, as the 





Answer.—Breaking strength = X 100 = 106,666 pounds. 


Answer.—Breaking load = 





= 57,600 pounds. 


186 BOULEDING CONSTKOGLLIOL. 


custom of the place would probably prevail in a dispute. It should 
also be stated whether or not openings are to be deducted ; as a rule 
rubble walls are figured solid, unless the opening exceeds 70 square 
feet. 

Occasionally rubble is measured by the cubic yard, or 27 cubic 
feet, and by the cord of 128 cubic feet. 

Stone backing 1s generally figured the same as rubble. 

Ashlar is almost invariably measured by the square foot, the price 
varying with the kind of work and size of stones. Openings are 
generally deducted, but width of jambs measured in with the face 
work. This custom varies, however, with different localities and kind 
of work. In common rock-face ashlar the wall is often figured solid 
unless the openings are of unusual size. : 

Flagging and slabs of all kinds are always figured by the square foot. 

Mouldings, belt courses and cornices are usually figured by the 
lineal foot, irregular shaped pieces by the cubic foot. All carving is 
figured by the piece. Some contractors figure all kinds of trimmings ~ 
by the cubic foot, varying the price according to the amount of labor 
involved. Others figure the cubic feet in all the stone to get the value 
of the rough stone, and then figure the labor separately—so much per 
lineal foot for mouldings, so much for columns, and a separate figure 
for carving. This is the most accurate method, and is usually 
employed by contractors for granite work. Of course considerable 
experience is necessary to know how much to allow for labor; the 
value of the stone itself can be very easily computed. 

213. Superintendence of Cut Stonework.—As with all other 
building operations, the superintendent needs to be very watchful in 
inspecting the cut stonework and its setting, to prevent defects and 
imperfect work being imposed upon him. When astone is once built 
into a wall it can only be removed at considerable expense and delay 
and much vexation, and it is therefore important that all defects be 
discovered before the stone is set. The superintendent must also be 
well posted on the various ways in which defects are covered up, so 
that he may discover them, if any exist, and have sufficient firmness 
to demand that all unsound or defective stones shall be replaced by 
sound ones, and that the work shall be done in the manner directed 
by the architect. 

Defects.—The following are the defects most likely to occur in 
cut stonework. 

Good grant‘es are liable to contain local defects, such as seams, 
black or white lumps called ‘“‘knots,” and also brown stains known 


COL STLONEAWORE. 187 


as sap. Any of these defects should cause the stone to be rejected. 
Seams may be detected by striking the stone with a hammer, and 
those which do not ring clearly should be rejected. 

In sandstones the most common defects are “sand holes” (which 
are small holes filled with sand, but without any cementing material, 
so that the sand soon washes out) and uneven color. Stones from 
the same quarry often vary considerably in color, and the superin- 
tendent must see that the color of the stone is uniform throughout. 

Patching.—Often in cutting stone a small piece will get broken 
from a large stone, and the contractor, rather than throw the stone 
away, will either stick the piece on again or cut out the fractured 
part and fit in a new piece. ‘The pieces are glued on with melted 
shellac and then rubbed with stone dust until they cannot be noticed 
by a casual glance, and the superintendent must look sharply at the 
stones to be sure that they have not been patched in this way. 

At first these patches are hardly noticeable and do no harm, but 
when the stone gets wet the patch becomes conspicuous, and in time 
the shellac in the joint is washed away and the patch drops off. 

When the damaged stone is large, and cannot be replaced except 
at great expense and considerable delay, the superintendent might 
consent to have it patched, but he should see that it is done right, 
and, where possible, a square hole should be cut in the stone and a 
corresponding piece tightly fitted in, and then cut to fit the stone or 
moulding. If on the corner of a stone the piece can generally be 
dovetailed, so that it will stay in place without the aid of shellac. 
If any patched stones are put into the building the superintendent 
should know of it beforehand, and, as a rule, it will be wise to consu!t 
the owner of the building about it before the stone is set. 

In the cutting of the stone the most common fault to be found is poor 
workmanship or too coarse a surface. Naturally the finer a surface is 
tooled or crandalled the greater the expense, hence contractors will 
generally finish the stone as coarse as they think the superintendent 
will pass. Very often, also, sufficient care is not taken in matching the 
ends of moulded belt courses, cornices, etc. The superintendent 
should insist that all the pieces are cut exactly to the same pattern, 
and that all edges are true and free from nicks. 

It is a very common occurrence to find some window sills that are 
not of sufficient width to be well covered by the wood sill. The back 
of the stone sills should extend at least 14 inches beyond the face of 
the wood sill, and the back of the wash should be cut to a straight 
line, without any holes or scant surfaces. 


188 BUILDING CONSTRUCTION. 


The ashlar, especially when rock-face, is apt to be too thin in 
places, and to have very poor bed joints. The superintendent should 
insist that the bed joints, top and bottom, be at least 3 inches wide 
at the thinnest part, and that they be cut square to the face of the 
work. He should also examine the stones to see that they have been 
cut so as to lay on their natural beds.“ The proper bonding and 
anchoring of the ashlar and trimmings should also receive careful 
attention. The anchoring of gable copings should be especially 
looked after, as it is not infrequent that such copings slide out of 
place and fall to the ground from neglect in this particular. One 
would naturally suppose that the builder himself would see that his 
work was done securely, if not handsomely ; but it seems to be a gen- 
eral fault amongst builders to trust a good deal to luck, and to use as 
few precautions to insure it as possible. In these days, when every- 
thing is done with a rush, there are also many builders that are igno- 
rant of the best methods of doing work, or that consider them unnec- 
essary and not “practical.” 

When finials or similar stones are cut in two pieces they should be 
secured together by iron dowels set in almost clear Portland cement. 
The superintendent should constantly bear in mind that stonework 
cannot be too well anchored and bonded. | 

The superintendent should also caution the foreman, when setting 
arches, columns, etc., not to let the mortar come within ? of an inch 
of the face of the stone. Moulded arches, particularly, need to be 
set with great care, as if the mortar comes out to the face the joint 
may be a little full at the edge and cause the: moulding to “sliver” 
or “spall” at the joints. It is not uncommon to see arch stones 
and columns cracked on account of neglect of this precaution. 

When the pointing is being done the superintendent must carefully 
watch the operation of raking out the joints to receive the pointing. 
The old mortar should be raked out to the depth of at least ? of an 
inch. If the work is not watched, however, it may be found in a 
year or two that the raking of the joints was only partially done, if 
not neglected altogether, and that the pointing mortar was only stuck 
on to the face of the joint. 

There will naturally be many other points in connection with the 
stonework that will require careful supervision to secure a good and 
durable job, but careful attention to those above noted will lead toa 
pretty thorough inspection of the whole work. 


CHAPTER VII. 
BRE GKeW: ORK. 


BRICKS. 


214. Bricks are more extensively used in the construction of 
buildings than any other material except wood. At the present.time 
brick and terra cotta architecture is decidedly in the ascendency, 
and a great deal of capital is invested in the manufacture of bricks 
of all kinds, shapes and colors. 

Good bricks possess the advantage over stone of being practically 
indestructible, either from the action of the weather, the acids of the 
atmosphere or fire; they may be had in almost any desirable shape, 
size or color, and are more easily handled and built into a wall than 
stone. Brickwork is also much cheaper than cut stonework, and in 
most localities is less expensive than common rubble. Unfortu- 
nately, however, all bricks cannot be classed under the above heading, 
as there are many that are soft and porous, and are far from durable 
when exposed to dampness. Except in very dry soils bricks are not 
as well adapted for foundations as stonework, nor can they be used 
for piers and columns thal support very heavy loads. 

As there are many different kinds and qualities of bricks, as well 
as good and bad methods of using them, the architect must know 
something about the manufacture of bricks, their characteristics and 
the best methods of using them to properly prepare his designs and 
specifications and to superintend the construction. 

215. Composition of Bricks.—Ordinary building bricks are 
made of a mixture of clay and sand (to which coal and other foreign 
substances are sometimes added), which is subjected to various pro- 
cesses, differing according to the nature of the material, the method 
of manufacture and the character of the finished product. 

After being properly prepared the clay is formed in moulds to the 
desired shape, then dried and burnt. 

The Clay—The quality of a brick depends principally upon the 
kind of clay used. The material generally employed for making 
common bricks consists of a sandy clay, or silicate of alumina, usu- 
ally containing small quantities of lime magnesia and iron oxide. If 


rgo BOILDING CONSTRUCTION. 


the clay consists almost entirely of alumina it will be very plastic, 
but will shrink and crack in drying, warp and become very hard 
under the influence of heat. 

Silica, when added to pure clay in the form of sand, prevents 
cracking, shrinking and warping, and allows a partial vitrification of 
the materials. The larger the proportion of sand present the more 
shapely and uniform in texture will be the bricks. An excess of sand, 
however, renders the bricks too brittle and destroys cohesion. 
Twenty-five per cent. of silica is said to be a good proportion. 

The presence of oxide of tron in the clay renders the silica and 
alumina fusible and adds greatly to the hardness and strength of the 
bricks. Iron also has a great influence upon the color of the bricks 
(see Section 229), the red color being due to the presence of iron. A 
clay which burns to a red color will make a stronger brick, as a rule, 
than one whose natural color when burnt is white or yellow. 

' “ Time has a twofold effect upon the clay containing it. Jt dimin- 
ishes the contraction of the raw bricks in drying, and it acts as a flux 
in burning, causing the grains of silica to melt, and thus binding the 
particles of the bricks together. Am excess of lime causes the bricks 
to melt and lose their shape. Again, whatever lime is present must 
be in a very divided state. Lumps of limestone are fatal to a clay 
for brickmaking. When a brick containing a lump of limestone is 
burnt the carbonic acid is driven off, the lump is formed into ‘ quick- 
lime’ and is liable to slake directly the brick is wetted or exposed to 
the weather. Pieces of quicklime not larger than pin heads have 
been known to detach portions of a brick and to split it to pieces. 
The presence of lime may be detected by treating the clay with a 
little dilute sulphuric acid. If there is lime present an effervescence 
will take place.” 

For the best qualities of pressed brick the clay is carefully selected 
both for chemical composition and color, and very often two or three 
qualities of clay from different sources are mixed together to obtain 
the desired composition. 

Clays of especially fine quality are often mixed and shipped to dis- 
tant portions of the country the same as other raw materials. 

216. Manufacture.—Wandmade Bricks.—Most of the common 
bricks used in this country, especially in the smaller towns and cities, 
are still made by hand. ‘The process consists of throwing the clay 
into a circular pit, where it is mixed with water and tempered with a 
tempering wheel worked by horse power, until it becomes soft and 
plastic, and is then taken out and pressed into the moulds by hand. 


BRICKWORK. 1gi 


Unless the clay already contains sufficient sand, additional sand is 
added to it as it is put into the pit, and often coal dust or sawdust is 
added to assist the burning. In some localities screened cinders are 
mixed with the clay. 

In moulding brick by hand the mould is dipped either in water or 
fine sand to prevent the bricks from adhering to the mould. If dipped 
in water the process is called “slop moulding,” and if in sand the 
bricks are called ‘sand struck.” The latter method gives cleaner 
and sharper bricks than those produced by “slop moulding.” 

After being shaped in the mould the bricks are laid in the sun, or 
in a dry house, to dry for three or four days, after which they are 
stacked in kilns and fired. 

When the green bricks are dried in the open air they occasionally 
get caught in a shower, which gives them a pitted effect, that is 
generally considered undesirable. Unless the edges are much 
rounded, however, it does not affect the strength of the bricks, and 
they may be used m the interior of the wall. 

217. Machine-made Bricks ——Where bricks are made on a large 
scale the work is now done almost entirely by machinery, commenc- 
ing with the mining of the clay by steam shovels and ending by burn- 
ing in patent kilns. 

A great variety of machines are now made for preparing the clay 
and for making the raw bricks; they differ more or less widely in 
construction and principle, but may be divided into three classes, 
according to the method of manufacture for which they are adapted. 

There are practically three methods employed in making bricks, 
viz.: The soft mud process, the stzff mud process and the dry clay 
process, and the machines are also classed under one of these head- 
ings. 

The general processes emp.oyed in these methods are as foliows : 

Soft Mud Process.—This is essentially the same process as that 
employed when the bricks are made by hand. When machinery is 
used the various steps are about as follows: As the clay is brought 
from the bank it is thrown into a pit (about 6 feet deep and 8x12 
feet in area) lined with planks ; water is then turned into the pit and 
the clay allowed to soak for twenty-four hours. Generally three pits 
are provided, so that the clay in one may be soaking while the second 
is being emptied and the third filled. If coal dust is to be mixed 
with the clay it is thrown into the pit in the proper proportion. After 
soaking twenty-four hours in the pit the clay is thrown out on to an 
endless chain, which carries it along to the machine, into which it 


192 BOLLDING CONSTRUCTION, 


falls. The upper part of a soft clay machine contains a revolving 
shaft, to which arms are affixed. These arms break up and thor- 
oughly work the soft clay, and it falls to the bottom of the machine, 
where revolving blades force it forward, and a plunger working up 
and down forces the clay into a mould placed under the orifice. The 
filled mould is then drawn or forced out on to a shelf or table and 
another mould placed under the machine. There are several styles 
of machines, but they all work on about this plan. Sometimes the 
clay is worked in a pug mill before being thrown into the machine. 

After being drawn from the machine the filled moulds are emptied 
by hand and the bricks taken to the dry shed. For drying soft mud 
bricks the “pallet’’ system is generally employed. The “pallets” 
are thin boards about 12x24 inches in size. The bricks are placed 
on these, and then the pallets are placed on racks, arranged so that 
the air may have free access to the bricks. The stacks should always 
be protected by a low roof. 

218. Stiff Mud Process.—The essential difference between this 
process and the foregoing is that in the stiff mud process the clay is 
first ground, or disintegrated, and only enough water is added to 
make a stiff mud. The mud, after being pugged, is forced through 
a die in a continuous stream, whose section is the size of a brick, and 
the bricks are then cut off. 

The process varies more or less in different yards and with dif- 
ferent clays, but when most thoroughly carried out the various 
steps in their order are as follows: First, the mining of the 
clay ; second, breaking up the lumps (generally in a pug mill) ; 
third, grinding of the clay, usually in a dry pan (see Section 221); 
fourth, tempering the clay, either in a separate pug mill or in the 
machine, and fifth, passing the clay through the machine and cutting 
off the bricks. ee F 

There are two primary types of stiff mud brick machines, viz.: 
The auger and plunger types. Of these the auger machines are the 
most numerous and generally considered the most satisfactory. The 
auger machine consists of a closed tube of cylindrical or conical shape, 
in which, on the line of the axis of the tube, revolves a shaft, to 
which is attached the auger and auger knives. The knives are so 
arranged as to cut and pug the clay and force it forward into the 
auger. The function of the auger is to compress and shape the clay 
and force it through the die. When the clay passes through the die 
it is compressed to as great an extent as it can be in its semi-plastic 
condition. The opening in the die is made the size either of the end 


BRICKWORK. 193 


or side of a brick, and a continuous bar of clay is constantly forced 
through it on toa long table. Various automatic arrangements are 
provided for cutting up this bar into pieces the size of a brick. If 
the section of the bar is the same size as the end of a brick the bricks 
are end cut; if the section of the bar is that of the side of a brick 
the bricks are side cut. With the end-cut brick the clay may issue 
from the machine in one, two, three or even four streams. 


From the cut-off table the green bricks pass to the off-bearing belt, 
from which they are taken to the represses or dryers. 


In the plunger brick machine the clay is forced into a closed box 
or pressing chamber, in which a piston or plunger reciprocates and 
forces the clay through the die. The action of this type of machine 
must of necessity be intermittent. When the plunger machine is 
used the clay is generally tempered in a pug mill before passing to 
the machine. 


219. Comparison of Soft Mud and Stiff Mud Bricks.— 
Soft mud bricks are made under little or no pressure, and are, there- 
fore, not as dense as the stiff mud bricks. It is claimed, however, that 
in the soft mud bricks the particles adhere more closely, and that when 
the brick are properly made and burned they are the most durable of 
all bricks. Soft mud bricks, after having lain in a foundation on the 
shore of a river for fifty-four years, were found in as perfect condi- 
tion as when laid. Soft mud bricks are also generally more perfect 
in shape than stiff mud bricks and better adapted for painting. 


Stiff mud bricks, owing to the nature of the clay and the details of 
manufacture, often contain laminations, or planes of separation, 
which more or less weaken the bricks. 


Those made by the plunger machine also sometimes contain voids 
caused by the air which occasionally passes with the loose clay into 
the pressure chamber, and, being unable to escape, passes out with 
the clay stream and renders it more or less imperfect. 

The manufacture of stiff mud bricks, however, is constantly 
increasing. 

In some localities soft mud bricks are the cheapest ; in others the 
stiff mud have the advantage. The difference in cost, however, is 
usually very slight. 

_ The soft mud bricks take longer to dry, but are more easily burnt. 

220. Lepressing.—Both soft and stiff mud brick are often repressed 


in a separate machine. Repressing reshapes the brick, rounds the 
corners if desired, trues it in outline and makes a considerable 


194 BOLILDING: CONSTACCLION,. 


improvement in its appearance. A properly formed stiff mud brick, 
however, is not improved in structure by repressing. 


221. Dry Clay Process.—This process is especially adapted to 
clays that contain only about 7 per cent. of moisture as they come 
from the bank, the clay being apparently perfectly dry. Wet claysare | 
sometimes dried and then submitted to the same process, but the 
expense of drying materially increases the cost of manufacture. 


The various operations generally employed in making brick by this 
process may be briefly described as follows: 


The first step is the mining of the clay, which may be done either 
by hand or steam shovel, according as circumstances may direct. 
After being mined the clay is generally stored under cover, so as 
always to have a supply on hand, and also to permit of further dry- 
ing and disintegrating. Sometimes, however, the clay is taken 
directly from the bank to the dry pan. 


Probably most of the dry press brick that are manufactured are 
made from two or more grades of clay, which are mixed in propor- 
tions determined by trial as the clay is thrown into the dry pan. 


From the dump the clay is thrown into a dry pan, which is a cir- 
cular machine about 4 feet in diameter and 2 feet deep, with a per- 
forated metal bottom. In this machine, or pan as it is called, are 
two wheels, which constantly revolve on a horizontal axis and grind 
the clay between them and the bottom of the pan, the pan itself 
revolving at the same time. The clay as it is ground passes through 
the holes in the bottom of the pan and falls on to a wide belt, which 
carries it above an inclined screen, on to which it falls. Such por- 
tions of the clay as are sufficiently finely ground fall through the 
screen on to another belt, and the coarser particles roll into the dry 
pan, to be again ground and carried on to the screen. 


The belt which receives the fine clay from the screen carries it to 
a mixing pan, which is a machine contrived to thoroughly mix the 
particles of the clay. From the mixing pan the clay falls into the 
hopper of the pressing machine, and from the hopper it falls into the 
moulds, where it is subjected to great pressure, which compresses it 
_ to the size of the brick and then pushes the pressed brick on toa 
table. From the table of the machine the bricks are taken by hand, 
placed on a barrow, or car, and transferred to the kiln. 

Different manufacturers may vary these operations somewhat, but 
the process, and also the machines, are essentially like the above in 
manufacturing pressed brick. 


BRICKWORK. 195 


The pressing machines are so constructed that the loose clay is 
made to evenly fill a steel box of the width and length of the intended 
brick, but much deeper. Into these boxes a plunger is forced, which 
compresses the clay until the desired thickness is reached, when the 
plunger stops. If the clay falls more compactly into one box, or 
mould, than into another, the brick from the first mould will be the 
denser, as the plunger falls just so far, no matter how much clay is in 
the mould. 

Moulded bricks are made in exactly the same way, the only differ- 
ence being that the box is made to give the shape of brick desired. 

Most of the pressed brick machines admit a small jet of steam into 
the clay just before it passes into the moulds to slightly moisten it. 

Bricks made by this process are very dense, and generally show a 
high resistance to compression, but the general opinion is that the 
particles do not adhere as well as when the clay is tempered, and 
that dry pressed bricks will not prove as enduring as soft mud 
bricks, although the former are now most extensively used for face 
bricks. 

When the term pressed bricks is used it should refer to bricks made 
by the dry process, although many so-called pressed bricks, or face 
bricks, are made by repressing soft mud bricks. 

222. Drying and Burning.—Bricks made by the soft mud pro- 
cess always have to be dried before placing in the kiln; those made 
by the stiff mud process are generally, although not always, stacked 
in a dry house from twelve to twenty-four hours. ‘The drying of the 
bricks is an important process, and where bricks are manufactured 
on a large scale the drying is generally accomplished by artificial 
means. 

After being sufficiently dried the bricks are stacked in a &/m and 
burned. 

Three styles of kilns are used for burning bricks, viz.: Up-draft, 
down-draft and continuous. 

Up-draft Kiin.—This is the style of kiln that was almost univer- 
* sally used in this country for burning bricks previous to 1870, and is 
_ still used more than either of the other kilns, especially in small yards 
where the bricks are manufactured by hand. 

The old-fashioned up-draft kiln is nothing but the bricks them- 
selves built into a pile about 20 to 30 feet wide and 30 to 40 feet 
long, and perhaps 12 or 15 feet high. The sides and ends of the 
piles are plastered with mud to keep in the heat, and the top is gen- 
erally covered with dirt and sometinss protected with a shed roof 


196 BUILDING CONSTRUCTION. 


The bricks are piled in such a way as to form a row of arched 
openings extending entirely across the kiln, and in these arches the 
fire is built. The dried bricks are loosely piled above these arches, 
and as the kiln is burnt those nearest the fire are so intensely heated 
as to become vitrified, while those at the top of the kiln are but 
slightly burned, with a gradual gradation of hardness between them. 
It is from this difference in the burning that the terms “arch brick,” 
‘red brick”? and “salmon brick” originated. As there is nothing 
but the natural tendency of heated air to rise to produce a draft, its 
direction is of course upward, hence the name. 


The modern up-draft kiln has permanent sides made of a 12 or 
16-inch brick wall laid in mortar, and heat is generated in ovens with 
iron grates built outside of the permanent walls, and only flames and 
heat enter the kiln through fire passages in the walls connecting the 
furnaces with the kiln proper. The top of the kiln is also paved 
with smooth, hard bricks, laid so as to form a close cover that can 
be opened or closed as desired. The bricks are piled in the same 
way as described above, the arches being left opposite the furnaces. 
With these improvements the bricks can be much more evenly 
burned and with a less consumption of fuel. The burning of a kiln 
of brick requires about a week. After the fires have been burning a 
sufficient length of time they are permitted to go out, and all the out- 
side openings tightly closed to keep out the cold air, and thus allow 
the bricks to cool gradually. It requires much skill and practice to 
burn a kiln of bricks successfully. 


223. Down-draft Ki/ns.—Kilns of this class require permanent 
walls and a tight roof. The floor must be open and connected 
by flues with a chimney or stack. These kilns are more often made 
circular in plan and in the shape of a beehive, although they are also 
made of a rectangular shape. ‘The heat is generated in ovens built 
outside of the main walls, and the flames and gases enter the kiln 
through vertical flues, carried to about half the height of the kiln. 
The heat, therefore, practically enters the kiln at the top and being 
drawn downward by the draft produced by the chimney, passes 
through the pile of bricks and the openings in the floor into the flues 
beneath, and hence to the chimney or shaft. It is claimed that all 
kinds of clay wares may be burnt more evenly in down-draft kilns, 
and terra cotta and pottery are almost always burnt in such kilns. For 
terra cotta and pottery the beehive shape is generally used, several 
kilns being connected with one stack. 


BRICKWORK. 197 


224. Continuous Kilns.—These kilns derive their name from the 
fact that the heat is continuous and the kilns are kept continuously 
burning. Continuous kilns are very different, both in construction 
and working, from the other two styles, and are also very expensive 
to construct. There are various styles of continuous kilns, each being . 
protected by letters patent. 

The most common type is that of two parallel brick tunnels 
connected at the ends. The outer walls are sometimes 8 feet 
thick at the bottom and 4 feet thick at the top. Various flues 
are built in these walls. The coal in continuous kilns is put in from 
the top. The bricks are piled in the kilns in sections, the sections 
being separated by paper partitions, and each section is provided 
with about four openings in the top for putting in the coal. After 
the kiln is started one section at a time is kept burning, and the 
heated gases are drawn through the next section so as to dry the 
bricks in that section before burning. ‘There are often twenty or 
more sections in one kiln, and while one section is being burnt and 
others dried, others are being filled and others are cooling or being 
emptied. 

Continuous kilns require a powerful draft to make them work suc- 
cessfully ; this draft is generally provided by a tall stack. 

The principal advantages claimed for the continuous kiln are that 
it takes less fuel to burn the bricks, and a greater percentage of No.1 
bricks are obtained than in other kilns. The question of the kind 
of kiln to be used, however, is principally one of economy to the 
manufacturer, as it makes no particular difference to the architect in 
what kind of a kiln the brick are burnt. 

225. Glazed and Enameled Brick.—These terms are used to 
designate bricks that have a glazed surface, the term ‘‘ enameled” 
being applied indiscriminately to all bricks having such a surface. 

There is, however, quite a difference between a glazed brick and 
an enameled brick. The true enamel is fused into the clay without 
an intermediate coating, and the enamel is opaque in itself, whereas 
a glaze is produced by first covering the clay with a “slip”’ and then 
with a second coat of transparent glaze resembling glass. 

In the manufacture of glazed bricks the unburnt brick is first coated 
on the side which is to be glazed with a thin layer of “slip,” which 
is a composition of ball clay, kaolin, flint and feldspar. The slip 
adheres to and covers the clay, and at the same time receives and 
holds the glaze. The glaze is put on very thin, and is composed of 
materials which fuse at about the temperature required to melt cast 


198 BUILDING CONSTRUCTION, 


iron, and leaves a transparent body covering the white slip. _ With a 
glazed brick it is the slip that gives the color of the brick, and as the 
slip covers the brick, the latter may be either red or white. Not all 
bricks, however, are suitable for glazing. 


Enameled bricks are made from a particular quality of clay, gen- 
erally containing a considerable proportion of fire clay. The enamel 
may either be applied to the unburnt brick or to the brick after it is 
burnt. The latter method, it is claimed, produces the most perfect 
brick. 

In burning, the enamel fuses and unites with the body of the brick, 
but does not become transparent, and therefore shows its own color. 


The manufacture of a true enameled brick is a much more expen- 
sive operation than that of making a glazed brick, besides being a 
very difficult operation. For this reason the glazed process is the 
one most generally employed, both in this country and in England. 


It is claimed that an enameled brick is more durable than a glazed 
brick and will not so readily chip or peel. The enamel is also the 
purest white. 

An enameled surface may be distinguished from one that is sim- 
ply glazed by chipping off a piece of the brick. The glazed brick 
will show the layer of slip between the brick and the glaze, while an 
enameled brick will show no line of demarkation between the body 
of the brick and the enamel. 

After the brick are in the wall none but an expert can distinguish 
between the two. Probably most of the so-called enameled bricks 
that have been used in this country are really glazed. 


The bricks are, of course, enameled or glazed only on one face, or 
on one face and one end. The color is generally white, although 
light blue and some other colors can be obtained. 


Until within a very few years nearly all the glazed bricks used in 
this country were imported from England, but there are now some 
eight or more factories in this country making them, and they produce 
more than half the glazed bricks now used in the United States. 


Enameled bricks generally differ in size from the ordinary bricks. 
The size of the English brick is 3 inches by g inches by 4# inches. 
Part of the American factories adhere to the English size, while 
others make the regular American size. 

The market price in Chicago for American and English glazed and 
enameled brick at the present time is $120 to $125 per M. for Eng- 
lish brick and $90 to $110 for American brick. 


BRICKWORK. 199 


The American glazed bricks are now more nearly perfect than 
when first put on the market, and appear to be giving satisfaction. 

The true enameled brick is just as good for external as for interior 
use. It will stand the most severe and climatic changes, and may 
be used in any climate and any situation. It is also fireproof. 

Both glazed and enameled bricks reflect light, acquire no odor, 
are impervious to moisture and form a finished and highly ornamental 
surface. 

Use.—Glazed bricks, on account of the above properties, are very 
desirable for facing the walls of interior courts, elevator shafts, toilet 
rooms, etc., and especially for use in hospitals. They may also be 
used with good effect in public waiting rooms, corridors, markets, 
grocery and butter stores, and wherever a clean, light and non- 
absorbent surface is desired, and also one that will stand drenching 
with water. ) 

226. Paving Bricks.—The introduction of brick paving for 
streets has led to the manufacture of this class of brick on an exten- 
sive scale. 

Paving bricks do not strictly come within the province of the 
architect, but as he may have occasion to use such bricks for paving 
driveways, etc., it is well to know something about them. 

Thin paving brick are also sometimes used for paving flat roofs of 
office buildings, apartment houses, etc. 

Paving bricks are most commonly made by the stiff clay process, 
and the bricks, after being cut from the bar, are generally, although 
not always, repressed to give them a better shape. The clay used 
for making these bricks is generally shale, almost as hard as rock, 
although it is sometimes found ina semi-plastic condition. With the 
shale a certain proportion—often 30 per cent.—of fire clay is gener- 
ally added. 

The principal difference in the manufacture of paving brick from 
common building brick is inthe burning. Paving brick, to stand the 
frost and wear, must be burnt to vitrification, or until the particles of 
the body have been united in chemical combination by means of 
heat. Besides being vitrified paving brick are also annealed, or 
tougbened, by controlling the heat and permitting the bricks to cool 
under certain conditions. 

Paving bricks, to enable them to endure the various sources of 
wear and disintegration to which they must be exposed in a street 
or driveway, or even on a roof, must be homogeneous and compact 
in texture, and must possess the qualities of vitrification and 


200 BUILDING GON STRCCTION. 


toughness. They should be free from loose lumps or uncrushed 
clay, or from extensive laminations, or fine cracks or checks of more 
than superficial character or extent, and should not be so distorted 
as to lay unevenly in the pavement. They should be free from lime 
or magnesia in the form of pebbles, and should show no signs of crack- 
ing or spalling after remaining in water ninety-six hours. They 
should have a crushing strength of not less than 8,000 pounds per 
square inch.* 

The best test of vitrification is that of porosity. A common-hard- 
burnt brick may be very dense and strong and still absorb 10 or 15 
per cent. of water. The same brick when vitrified will hold very 
little water, and should absorb none, in the chemical sense of the 
word. 

Engineers, when specifying brick for pavements, generally limit 
the absorption to 4 per cent., and sometimes to 2 per cent., the brick 
to be first dried to 212° F. Paving bricks are made that do not 
absorb more than 1 percent. It is claimed, however, that a brick 
may be vitrified and still absorb as high as 6 or 8 per cent., owing to 
its containing considerable air spaces. The density or specific grav- 
ity also gives a valuable idea of the degree of vitrification of paving 
brick. A great density or high specific gravity usually indicates 
durability. 

For testing the toughness and resistance to wear under the horses’ 
feet a machine called a “rattler” is used. The rattler resembles a 
barrel, and into it several bricks are put together with pieces of scrap 
iron and the rattler is then revolved rapidly for a given length of time. 
The amount that the bricks lose in weight is taken as the test of their 
durability. 

It is claimed by good authorities that the rattler test when prop- 
erly conducted is the most important test for durability, and that any 
brick which will successfully withstand this test will be found sat- 
isfactory. 

227. Fire Bricks.—Fire bricks are used in places where a very 
high temperature is to be resisted, as in the lining of furnaces, fire- 
places and tall chimneys. ‘The ordinary fire brick used for the above 
purposes is made from a mixture of about 50 per cent. raw flint clay 
and 50 per cent. plastic clay, the proportion varying with different 
manufacturers. The bricks are made both by the stiff mud and dry 
press processes, and also by the soft mud process with hand moulding. 
It is claimed that the last process gives the most perfect brick. 





*H. A. Wheeler, E. M.,, in the Clay Worker, August, 1895. 


BRICKWORK. 201 


Fire bricks, to admit of rapid absorption or loss of heat, should be 
Open grained or porous, and at the same time free from cracks. 
They should also be uniform in size, regular in shape, homogeneous in 
texture and composition, easily cut and infusible. 

Fire bricks are generally larger than the ordinary building brick. 

228. Classes of Building Brick.—Common Brick.—This term 
includes all those brick which are intended simply for constructional 
purposes, and with which no especial pains are taken in their manu- 
facture. There are three grades of common brick, determined by 
their position in the kiln. 

Arch or hard brick are those just over the arch, and which, being 
near the fire, are usually heated to a high temperature and often vit- 
rified. They are very hard, and if not too brittle are the strongest 
brick in the kiln. They are often badly warped, so that they can 
only be used for footings and in the interior of walls and piers. 

Red or well-burned brick should constitute about half the brick in 
the ordinary up-draft kiln, and when made of clay containing iron 
should be of a bright red color. For general purposes they consti- 
tute the best brick in the kiln. 

Salmon or soft brick are those which form the top of the kiln and 
are usually underburned. ‘They are too soft for heavy work or for 
piers, though they may be used for filling in light walls and for lining 
chimneys. 

The strength and hardness of common bricks of all grades vary 
greatly with the locality in which they are made on account of the 
difference in the clay. Some of the salmon brick of New England 
are fully as hard and strong as the red bricks of other localities, par- 
ticularly in the West. As the color of a brick may be due more to 
the presence or absence of iron than to the burning, it cannot be used 
as an-absolute guide to the quality of the brick. 

Stock brick are a handmade brick intended for face work, and 
with which greater care is taken in the manufacture and burning 
than with common brick. In the East they are sometimes called 
Jace brick. 

Pressed brick or face brick generally refers to brick that are 
made in a dry press machine, or that have been repressed. They 
are usually very hard and smooth, with sharp angles and corners and 
true surfaces ; they may be either stronger or weaker than common 
_ brick, according to the character of the clay and the degree to which 
they are burnt. Pressed brick are not usually burnt as hard as com- 
mon brick, and are, therefore, sometimes not as durable. Pressed 


202 BUILDING CONSTRUCTION. 


brick cost from two to five times as much as common brick, and are, 
therefore, generally used only for the facing of the wall. 

Moulded, arch and circle brick are special forms of pressed brick. 
A great variety of moulded or ornamental bricks are now made, by 
means of which mouldings and cornices may be built entirely of 
brick. Most of the companies manufacturing pressed bricks will also 
make any special shape of brick from an architect’s designs. Arch 
bricks are made in the form of a truncated wedge and are used for 
the facing of brick arches. They can be made for any radius desired. 
Circle brick are made for facing the walls of circular towers, bays, 
etc. The radius of the bay should be given when ordering these 
brick. 

229. Color of Bricks.—The color of common bricks depends 
largely upon the composition of the clay used and the temperature 
to which they are burnt. Pure clay, free from iron, will burn white, 
but the color of white bricks is generally due to the presence of lime. 
Iron in the clay produces a tint which varies from light yellow to 
orange and red, according to the proportion of iron contained in the 
clay. A clear bright red is produced by a large proportion of oxide 
of iron, and a still greater proportion of iron gives a dark blue or 
purple color, and when the bricks are intensely heated the iron melts 
and runs through the bricks, causing vitrification and giving increased 
strength. ‘The presence of iron and lime produces a cream or light 
drab color. Magnesia produces a brown color, and when in the 
presence of iron makes the brick yellow. 

The color of pressed brick is, of course, the same as that of com- 
mon bricks made from the same clay; but pressed bricks are also 
colored artificially, either by mixing together clays of different chem- _ 
ical composition, or by mixing mineral paints or mortar colors with 
the clay in the dry pan. Bricks are also sometimes colored by 
applying a mineral pigment to the face of the bricks before burning. 
This latter method, however, is not very satisfactory. At the pres- 
ent time the use of colored bricks is very popular, and face brick are 
made in all shades of red, pink, buff, cream and yellow. Some of 
these colors are very effective when used in an artistic manner, but 
the use of colored bricks has been much abused, and it requires a 
fine sense of color to use them effectively, especially where two or 
more shades are used in the same building. 

230. Size and Weight of Building Bricks.—In this coun- 
try there is no legal standard for the size of bricks, and the dimen- 
sions vary with the maker and also with the locality. In the New 


BRICKWORK. 203 
England States the common brick averages about 7?x3}?x2+ inches. 
In most of the Western States common bricks measure about 
84x44x24 inches, and the thickness of the walls measures about 9, 
13, 18 and 22 inches for thicknesses of 1, 13, 2 and 24 bricks. The 
size of 2ll common bricks varies considerably in each lot, according 
to the degree to which they are burnt; the hard bricks being from 
4 to 3°; of an inch smaller than the salmon bricks. 

Pressed brick or face brick are more uniform in size, as most of 
the manufacturers use the same size of mould. The prevailing size 
for pressed brick is §3x44x22 inches. Pressed bricks are also made 
14 inches thick and 12x4x1$ inches, the latter size being generally 
termed Roman brick, or tile. 

Pressed. bricks should be made of such size that two headers and a 
joint will equai one stretcher, and it 1s also desirable that the length 
of a brick should be equal to three courses of bricks when laid. The 
National Brickmakers’ Association in 1887 and the National Traders’ 
and Builders’ Association in 1889 adopted 8}x4x2+ inches as the 
standard size for common bricks, and 82x4}xz2} for face bricks. 

As all bricks shrink more or less in burning, it is generally neces- 
sary to assort even pressed bricks into piles of different thicknesses 
in order to get first-class work. 

The weight of bricks varies considerably with the quality of the 
clay from which they are made, and also of course with their size. 
Common bricks average about 44 pounds each, and pressed bricks 
vary from 5 to 54 pounds each. 

231. Requisites of Good Brick.—:i. Good building brick 
should be sound, free from cracks and flaws and from stones and 
lumps of any kind, especially lumps of lime. 

2. To insure neat work the bricks must be uniform in size and the 
surfaces true and square to each other, with sharp edges and angles. 

3. Good bricks should be quite hard and burnt so thoroughly that 
there is incipient vitrification all through the brick. A sound, well- 
burnt brick will give out a ringing sound when struck with another 
or with a-trowel. A dull sound indicates a soft or shaky brick. 
(This is a simple and generally sufficient test for common bricks, as 
a brick with a good ring is ordinarily sufficiently strong and durable 
for ary ordinary work.) 

4. A good brick should not absorb more than one-tenth of its 
weight of water. The durability of brickwork that is exposed to the 
action of water and frost depends more largely upon the absorptive 
power of the bricks than upon any other condition ; hence, other 


204 BUILDING CONSTRUCTION. 


conditions being the same, those bricks which absorb the least 
amount of water will be the most durable in outside walls and foun- 
dations. Asarule the harder a brick is burnt the less water it will 
absorb. “Very soft, underburned bricks will absorb from 25 to 35 
per cent. of their weight of water. Weak, light red ones, such as are 
frequently used in filling in the interior of walls, will absorb about 20 
to 25 percent., while the best bricks.will absorb only 4 or 5 per cent. 
A brick may be called good which will absorb not more than to per 
Cente. 

232. Strength.—A good brick, suitable for piers and heavy 
work, should not break under a crushing load of less than 4,000 
pounds per square inch; any additional strength is not of great 
importance, provided the brick meets the preceding requirements. 
In a wall the transverse strength is usually of more importance than 
the crushing strength. For a good brick the modulus of rupture 
should not be less than 720 pounds; or, in other words, a brick 8 
inches long, 4 inches wide and 2} inches thick should not break 
under a centre load of less than 1,620 pounds, the brick laying flat- 
ways and having a bearing at each end of 1 inch and a clear span of 
6 inches. A first-class brick should carry 2,250 pounds in the centre 
without breaking, and bricks have been tested which carried 9,700 
pounds before breaking. 


- BRICKWORK. 


233. To build any kind of a brick structure so as to make a strong 
and durable piece of work, it is necessary to have a bed of some kind 
of mortar between the bricks. Brickwork, therefore, consists both of 
bricks and mortar, and the strength and durability of any piece of 
work will depend upon the quality of the bricks, the quality of the 
mortar, the way in which the bricks are laid and bonded and whether 
or not the bricks are laid wet or dry. 

The strength and stability of a wall, arch or pier also depends upon 
its dimensions and the load it supports, but for the quality of the 
brickwork only the above items need be considered. 

The kinds and qualities of mortars used for laying brickwork are 
described in Chapter IV. The majority of the brick buildings in 
this country are built with common white lime mortar, to which 
natural cement is sometimes added. For brickwork below ground 
either hydraulic lime or cement mortar should be used. (See Sec- 
tions 107 and 127.) 





* Ira O. Baker, in ‘‘ Masonry Construction,” p. 38. 


BRICKWORK. 205 


The function of the mortar in brickwork is threefold, viz.: 

1. To keep out wet and changes in tempera.ure by filling all 
crevices. 

2. To unite the whole into one mass. 

3. To form acushion to take up any inequalities in the bricks 
and to distribute the pressure evenly. 

The first object is best attained by grouting, or thoroughly “ flush- 
ing’ the work ; the second depends largely upon the strength of the 
mortar, and the third is affected principally by the thickness of the 
joints. 

234. Thickness of Mortar Joints.—Common brick should 
be laid in a bed of mortar at least 33; and not more than 2 of an inch 
thick, and every joint .and space in the wall not occupied by other 
materials should be filled with mortar. The best way of specifying 
the thickness of the joint is by the height of eight courses of brick 
measured in the wall. This height should not exceed by more than 
2 inches the height of eight courses of the same brick laid dry. 

As common bricks are usually quite rough and uneven, it is not 
always easy to determine the thickness of a single joint, but the vari- 
ation from the specifications in any eight courses that may be selected 
should be very slight. It is not uncommon tosee joints ? inch thick 
in common brickwork, especially where the work is not superit- 
tended. 

Pressed bricks, being usually quite true and smooth, can be laid 
with a 4-inch joint, and it is often so specified. A ;',-inch joint is 
probably stronger, however, as it permits filling the joint better. 

235. Laying Brick.—A. Common Brick.—The best method of 
building a brick wall is to first lay the two outside courses by spread- 
ing the mortar with a trowel along the outer edge of the last course 
of brick to form a bed for the brick to be laid, and scraping a dab of 
mortar against the outer vertical angle of the last brick laid, and then 
pressing the brick to be laid into its place with a sliding motion, 
which forces the mortar to completely fill the joint. 

Having continued the two outer courses of brick to an angle or 
opening, the space between the courses should be filled with a thick 
bed of soft mortar and the bricks pressed into this mortar with a 
downward diagonal motion, so as to press the mortar up into the 
joints. This method of laying is called ‘‘shoving.” If the mortar 
is not too stiff, and is thrown into the wall with some force, it will 
completely fill the upper part of the joints, which are not filled by 
the shoving process. A brick wall laid up in this way will be very 


\ 


206 BOUILDINGCONSLAUCLION 


strong and difficult to break down. A very common method of lay: 
ing the inside brick in a wall is to spread a bed of mortar and on this 
lay the dry brick. If the bricks are laid with open joints and thor- 
oughly slushed up it makes very good work, but unless the men are 
carefully watched the joints do not get filled with mortar, and the 
wall will not be as strong as when.the bricks are shoved. 

236. Grouting. —Another method of laying the inside brick is to 
lay them dry on a bed of mortar, as described above, and then fill all 
the joints full of very thin mortar. This is called grouting, and, 
while it is condemned by many writers, the author knows from 
actual experience that when properly done it makes very strong work. 
No more water than is necessary to make the mortar fill all the joints 
should be used, and grouting should not be used in cold or freezing 
weather. Grouting is especially valuable when very porous bricks 
are used. (See Section 132.) 





Fig. 122. Fig. 123. 


237. Striking the Joints——For inside walls that are to be plastered 
the mortar projecting from the joints is merely cut off flush with the 
trowel. For outside walls and inside walls, where the brick are left 
exposed, the joint should be “‘struck”’ as in Fig. 122. This is done 
with the point of the trowel, by holding the trowel obliquely. Fig. 123 
is the easiest joint to make, and is the one generally made unless 
Fig. 122 is insisted on. For inside work it makes no particular dif- 
ference which joint is used, but for outside work Fig. 122 is much 
more durable, as the water will not lodge in the joint and soak into 
the mortar, as will be the case when the joint is made as in Fig. 123. 

When “struck joints” are desired they should always be specified, 
otherwise the brick mason may claim that he is not obliged to strike 
them. 

B. Face Brick.—Face brick are usually laid in mortar made of 
lime putty and very fine sand, often colored with a mineral pigment. 


BRICKWORK. 2047 


(See Sections 104 and 148.) The joints should not exceed ;’; of an 
inch, except in cases where a horizontal effect is desired, when the 
horizontal joints are made } of an inch and the vertical joints as 
close as possible. For very fine work the joints are sometimes kept 
down to $ of an inch. The joints should be carefully filled with 
mortar and either ruled at once with a small jointer or else raked out 
and left for pointing. In very particular work a straight-edge is held 
under the joint and the jointer drawn along on top of it, thus mak- 
ing a perfectly straight joint. This is called ~w/ed work. In laying 
the soffits of arches and vaults with face brick the joint cannot be 
finished until the centre is removed, therefore the joint should not 
be quite filled with mortar, and must be raked out and pointed after 
the centre is removed 


Many pressed brick and some handmade bricks have one or more 
depressions in the larger surfaces of the brick to give a better key to 
the mortar. When the depressions are only on one side of the brick 
that side should be uppermost. 


When building of face brick a piece of brickwork at least 2 feet 
high and 2 feet 6 inches long should be built up in an out-of-the-way 
place as soon as the first lot of brick is delivered, as a sample piece, 
and all stone er terra cotta work should be made to conform abso- 
lutely to the brickwork. 


Sorting.—Pressed brick, even from the same kiln, generally vary 
in size and shade, the darker brick often being ;; inch thinner than 
the lighter brick and also shorter. If, therefore, a perfectly uniform 
color is desired the bricks must be sorted into piles, so that each lot 
will be of the same shade, and each shade laid in the building by 
itself. The change between the different shades should occur, where 
possible, at a string course or at an angle in the building. Many 
architects, however, consider that a handsomer and brighter wall is 
secured by mixing the different shades, so that hardly two bricks of 
exactly the same shade will come together, although if the mixing is 
weil done the general tone of the wall at a distance will be uniform. 
With colored bricks this haphazard method undoubtedly gives the 
most artistic and sparkling effect. 


Circular Work.—For circular walls, faced with pressed brick, the 
bricks should be made of the same (or very nearly the same) curva- 
ture as the wall. Many pressed brick manufacturers carry circle 
brick of different curvatures in stock, and any curvature can be 
made to order. 


208 BOTLLDING CON SLRUCLION, 


When circle brick cannot be obtained straight bricks may be used 
for curvatures with a radius of 12 feet or over, and for lesser radii 
half brick or headers should be used. 

238. Brick to be Wet.—Mortar, unless very thin, will no? 
adhere to a dry, porous brick, because the brick robs the mortar of 
its moisture, which prevents its proper setting. On this account 
brick should ever be laid dry, except in freezing weather, and in hot, 
dry weather it is impossible to get the bricks teo wet. When using 
very porous brick the wetting of the brick is of more consequence in 
obtaining a strong wall than ‘any other condition. As wetting the 
bricks greatly increases their weight and consequently the labor of 
handling them, besides making it harder on the hands, masons da 
not like to wet them unless they are obliged to, and it should always 
be specified and insisted upon by the superintendent, except in freez- 
ing weather. 

Pressed brick cannot very well be laid dry, and the masons gener- 
ally wet them for their own convenience, but they will often tell all 
sorts of stories to escape wetting the common brick. 

239. Laying Brick in Freezing Weather. — Brickwork 
should never be laid when the temperature is be ow 32°, and if it is 
below 40° and liable to fall below, 32° at night, salt should be mixed 
with the mortar and the bricks /eated before laying, and the top of 
the wall covered with boards and straw at night. It is much better 
not to lay brick in freezing weather unless the delay occasioned 
involves a great loss. In building large buildings in the winter time 
one-third Portland cement should be added to the mortar, then it 
will not be damaged by freezing. It is necessary that the surface of 
the bricks be clean and free ‘from frost, snow or ice, when they are 
laid, otherwise the mortar will not adhere to them. 

If the mortar in the upper courses becomes frozen over night, 
those courses should be taken down and the bricks thoroughly 
cleaned before being used again. For the effect of freezing on mor- 
tar see Section 139. 

Protection from Storms.—Wet without frost does not injure the 
strength of brickwork, but if rain strikes the top of a wall it will wash 
the mortar out of the joints and stain the face of the wall. 

The excessive wetting of a wall is also injurious, as it takes a long 
time for the wall to dry out, and it is likely never to dry to a uni- 
form color. For this reasun the top of the wall should always be 
protected at night, or when leaving off work, by boards placed so as 
to shed the water.’ 


BRICKWORK. 209 


240. Ornamental Brickwork.—The ornamental effects to be 
obtained by the varied use of bricks are exceedingly numerous. First, 
there are the constructive features, such as arches, impost courses, 
pilasters, belt and string courses, cornices and panels; then there is 
a large field for design in surface ornament, by means of brick of 
different shades or color, laid so as to form a pattern. 


For the constructive features both plain and moulded bricks may 
be used, although only very plain effects can be produced by plain 
brick alone. 

In nearly all of our large cities, and especially those near which 
pressed brick are manufactured, a great variety of moulded bricks 
can be obtained, by means of which it is possible to construct almost 
any moulding, belt course, etc., that may be desired. 


Belt courses and cornices, and in fact any moulded work built of 
brick, is much cheaper than the same mouldings cut in stone. 
In designing brick details a point to be observed 
, is that the projection should be kept small. 





The top of all belt courses should have a wash 
on top, as shown in Fig. 124. 

The top course, W, should be laid as stretchers 
when the projection is not over 3 inches to reduce 
the number of end joints, and the bricks should 
also be laid in cement mortar, so that the mortar 
in the end joints will not be washed out. 

If Wis a stretcher course, at least every other 
brick in the course below should be a header. 

If a beveled brick cannot be obtained for the top course, and a 
plain brick must be used, its upper surface should be protected by 
sheet lead built into the second joint above it, as shown at A, Fig. 125, 
or the top of the bricks may be plastered with Portland cement, as 
shown at 4. Unless some such precaution is taken to protect the 
top of the projecting brick from the wet, the rain water will after a 
while soften the mortar in the joint, /, and penetrate into the wall. 
The end joints in the belt course are always liable to be washed out. 


Belt courses and cornices should always be well tied to the wall by 
using plenty of headers or iron ties. The top of the wall should also 
be well anchored to the rafters or ceiling joist by iron anchors, as the 
projection of the cornice tends to throw the wall outward. 


In using moulded brick in string courses and cornices it is more 
economical to use bricks that can be laid as stretchers, as it, of 


210° BUILDING CONSTAUCTION. 


course, takes a less number of stretchers than of headers to fill a given 
length, and the bricks cost the same. 

One of the greatest objections to brick mouldings is the difficulty 
of getting them perfectly straight and true. Nearly all moulded 
brick become more or less distorted in moulding and burning, so 
that when laid the abutting ends do not match evenly, and the 
moulding presents the appear- 
ance shown in Fig. 126. 







Ki, 
IW be Some makes of brick, how- 
YG, ever are guie ates on these 
qe defects, and before selecting 
moulded bricks to be used in 
this way the architect should 
B WWW endeavor to ascertain which 
UML makes are the truest and give 
the most perfect work. 
Fig. 125. 
By being very careful in lay- 
ing the bricks to average the defects, and by ruling the joints, the 
effect of the distortion may be largely overcome. Headers do not 
show the distortion as much as stretchers. 
241. Cornices.—For brick buildings with a parapet wall and 
flat roof a brick cornice is generally the most appropriate unless one 
of terra cotta can be afforded. A brick cornice is certainly to be 





Fig. 126. 


preferred to one of galvanized iron or wood, as it is more durable 
and will not require painting, besides being a more appropriate use 
of material. 

In cornices where considerable prcjection is desired it is almost 
always safe to adopt some corbeled treatment, building the corbels 
up by slightly projecting each course. Dentil courses 1n cornices 
and string courses are also very effective and easy to lay, 


BRICKWORK. 














































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Fig. 128. 


DESIGNS FOR BRICK CORNICES. 


[From the Brickbuzlder.] 


212 BUILDING CONSTRUCTION. 


Figs. 127 and 128 are suggestions for moulded brick cornices for 
three and four-story buildings, and Fig. 129 one of plain bricks for a 
two-story building with a low pitch roof. Fig. 130 shows a section 
of a simple brick cornice that the author has used on brick churches 
having a pitch roof. 

Decorative brickwork should always be executed in smooth, regu- 
lar brick of even color, as uneven colors and rough brick mar the 
effect of light and shade and detract from the design. 

All brick walls or cornices should be capped by a projecting cop- 
ing of metal, terra cotta or stone, provided with a hollow drip to 
throw off the water. 








Fig. 130. 


For brick cornices a copper or galvanized iron crown mould, such 
as is shown in Figs. 127 and 129, is very appropriate. The metal 
should be carried over the top of the wall (if a parapet) and down 5 
inches at the back. 

If the wall terminates as shown in Fig. 128 the upper courses 
should be laid in cement mortar and the top well plastered with 
Portland cement. This will protect the wall for several years, but is 
not as lasting as terra cotta or metal. 

242. Surface Patterns.—Surface patterns, or diaper work, are 
very common in brick buildings in Europe, and they have lately beer 
introduced to a considerable extent in this country. 


BRICKWORK. 213 


Their chief object is to give variety to a plain wali space. When 
used in exterior walls they should not be so marked as to make the 
pattern insistent and thus interfere with other features of the building. 











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Fig. 131. 


Usually sorting the brick into light and dark shades, or varying 
the color of the mortar in which the pattern is laid, will be sufficient 
for any surface decoration, the best success in this class ot decora- 
tion being obtained by using comparatively simple designs and quiet 
contrasts of color. 


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Fig. 132. 


If different colors are used the greatest care must be exercised in 
their selection, and even with care and thought it is not granted to 
all architects to use color nicely. 

One of the best opportunities for the use of color lies in the direc- 
tion of pattern work for frieze and band courses. 


214 BUILDING CONSTRUCTION. 


Fig. 131 shows a simple brick diaper for a frieze, and Figs. 132 

and 133 an ornamental panel and chimney, the latter designed by 
Mr. H. P. Marshall, architect. 
' Surface patterns should generally be 
flush with the wall. When used as in 
Fig. 133 the pattern may project } inch 
from the surrace or panels. 

Diaper work may also be used with good 
effect on interior brick walls of waiting 
rooms, corridors, public baths, etc. 


CONSTRUCTION OF WALLS. 


243. The proper construction of a brick 
building involves many things besides the 


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Fig. 133: 


mere laying of one brick on top of another 
with a bed of mortar between. The man- 
ner of laying or bedding the bricks and 
the general methods of doing the work hav- 
ing been considered, we will next consider 
the points in construction required to 
obtain a strong and durable wall, and the 
precautions to be observed to prevent set- 


tlements and cracks and adapting the work 
to the purposes for which it is intended. 
Aside from the quality of the materials and the character of the 
work, the bonding of a wall has the most to do with its strength. 
Bond.—Bond in brickwork is the arrangement of the bricks 
adopted for tying all parts of the wall together by means of the 






WAU 
WiWe4D 






—= a OO ee ee be 


EEE OSE TTS 





Fig. 134.—Common Bond. 


Fig. 135. 


weight resting on the bricks, and also for distributing the effects of a 
concentrated weight over an ever-increasing area. 

Common Bond.—A brick laid with its side parallel to the face of 
the wall is called a stretcher ; when laid at right angles to the wall, 


BRICKWORK. 215 


so that its end is parallel to the face of the wall, it is called a header. 
Common brick walls in this country are almost universally built by 
laying the brick all stretchers for from four to six courses and then 
laying a course of headers as shown in Fig. 134. When the wall is 
more than one brick in thickness the heading courses should be 
arranged either as at 4 or #, Fig. 135. For first-class work the wall 
should be bonded with a heading course every sixth course. 

2h 





Fig. 136.—Plumb Bond. 


244. Plumb or diagonal bond (sometimes called American bond) is 
generally used when the wall is faced with pressed brick. The face 
brick are laid all stretchers with the joints plumb above each other 
from bottom to top of the wall, as shown at 4, Fig. 136. The bond- 
ing of the face brick to the common brick is accomplished by clip- 
ping off the back corners of the face brick in every sixth or seventh 
course and laying diagonal headers behind, as shown at B, Fig. 136. 
This does not make as strong a tie 
as a regular header, but if carefully 
done it appears to answer the pur- 
pose. Very often where this bond 
is used only one corner of each face 
brick in the outside course is 
clipped, so that only half as many 
diagonal brick, or headers, as are 
indicated in Fig. 136 are used. 
This of course does not make as strong a bond as when both of the 
back corners are clipped. In walls exceeding one story in height the 
architect should see that both corners are clipped. The strongest 
method of bonding for face brick is by the Flemish or cross bond, 
described in Section 245. The objection to these bonds, however, is 
the increased expense occasioned by using so many face brick head- 
ers and also that the face brick and common brick do not usually lay 
to the same heights, so that it would be necessary to clip the com- 
mon brick if face brick headers were used in every course, or even 
every third or fourth course. 





Fig. 137. 


216 BUILDING CONSTRUCTION. 


Face bricks, when laid as in Fig. 136, are often tied to the back: 
ing by pieces of galvanized iron or tin (as shown in Fig. 137), which 
have their ends turned over a stiff wire about 4 inches long. The 
wire is not absolutely essential, but should always be used in firsts 
































| 

ft) i 
it le 
Hi 





igs 
is see 7 
in 





Fig. 138. 


class work. A still better tie for bonding face brick to the backing 
is the Morse Wall Tie, shown in Fig. 138. 

This tie is made from 2 and 4-inch galvanized steel wire 7, 9, 12 
and 16 inches in length. The 3%-inch wire is used for ordinary 
pressed brickwork, and the 4-inch size for very closely laid work. It 
is now very extensively used in the Eastern portion of the country. 


ae hai ree 
ee eee 
a es ag] ET ae | 


ete ale 
po 
Fig. 139.—English Bond. Fig. 140.—Flemish Bond, 


One advantage obtained in using the metal tie is that it is not nec- 
essary that the joints in the face work and backing shall be on the 
same level, as the ties can be bent to conform to the difference in 
level, as shown in Fig. 137. Face brick bonded in this way should 
be tied at least every fourth course with one tie to each face brick. 

245. Lnglish bond (Fig. 139) isa method of bonding much used 
n England, and consists of alternate heading and stretching courses. 


ae Sew 


BRICKWORK. 217 


It is probably the strongest method of bonding common brick, but it 
is not applicable where face brick are used. It does not make very 
attractive work, and is scarcely ever used in this country. 

Flemish bond, shown in Fig. 140, consists of alternate headers and 
stretchers in every course, every header being immediately over the 
centre of a stretcher in the course below ; closers (a) are inserted in 
alternate courses next to the corner headers to give the lap. This 
makes a very strong bond, but cannot be used with face brick unless 
the common brick are a little smaller than the face brick, so as to lay 
up even courses. A modification of this bond, consisting of laying 
every fifth course of alternate headers and stretchers, is sometimes 
adopted. It makes stronger work than the diagonal bond and looks 
about as well. 

Linglish cross bond is a variety of English bond said to be much used 
in Holland, its name being suggested by the appearance of the sur- 
face, on which the bricks seem to arrange themselves into St. Andrew’s 

crosses. It only differs from ordinary 
; English bond in that the stretchers 


of the successive stretching courses 
break joint with each other on the 
=e face of the wall, as well as with the 


EBs ee [ headers in the adjoining courses, as 


—Cross B 
LES Bian ee shown in Fig. 141. This makes a 


much better looking wall than the ordinary English bond. 

246. Hoop Iron Bond.—Pieces of hoop iron are often laid flat 
in the bed joints of brickwork to increase its longitudinal tenacity 
and prevent cracks from unequal settlement. The ends of the iron 
should be turned down about 2z inches and inserted into the vertical 
joints. Nothing less than No. 18 iron should be used, and the hold- 
ing power of the ties may be greatly improved by dipping in hot tar 
and then covering with sand. Hoop iron bond is strongly to be rec- 
ommended for strengthening brick arches and the walls above, also 
the walls of towers, etc., and where an interior wall joins an external 
wall. ‘Twisted iron bars are still better for this purpose. 

247. Anchoring the Wall.—Although this belongs more espe- 
cially in the carpenter work, it is ment.oned here as a very important 
point in securing the stability of the wall and preventing its inclin- 
ing outward. 

Brick walls should be tied to every floor at least once in every 6 
lineal feet, either by iron anchors, solidly built into the wall asd 
spiked to the floor joist, or by means of a box anchor or joist hanger. 


218 BUILDING CON STROGZLON, 


. The forms of iron anchors most commonly used for this purpose 
are those shown in Fig. 142, the one shown at @ being the most com- 
mon, and about as good a style as any. The anchor shown at 6 
answers equally as well, but costs a very little more. Anchors like @ 
and & are spiked to the sides of the floor joist and built into the wall, 
as shown in Fig. 143. 

If the wall is a side or rear wall, where the appearance is not of 
much consequence, it is better to have the anchor pass clear through 
the wall, with a plate on the outside, as 
such an anchor gets a much better hold 
on the wall than is possible when it is 
built into the middle of the wall. The 
cheapest form of anchor for this purpose 
is that shown at ¢, which has a thin plate 
of iron doweled and upset on the outer 
end. ‘This style of anchor may also be 
used for building into the middle of the 
wall. 


For anchoring the ends of girders, or 
where a particularly strong anchor is 
desired, the form shown at @ is undoubt- 
edly the best. This anchor is made 
from a #-inch bolt, flattened out for 
spiking to the joist and provided with a 
cast iron star washer. It possesses the 
advantage of having a nut on the outer 
end, which can be tightened up if 
_ desired after the wall is built. 

All of these anchors should be spiked to the side of the joist or 
girder, xear the bottom, as shown in Fig. 143. The nearer the anchor 
is placed to the top of the joist, the greater will be the destructive 
effect on the wall by the falling of the joist, as shown in Fig. 143 A. 

For anchoring walls that are parallel to the joist the anchor must 
be spiked to the top of the joist, and should either be long enough to 
reach over two joist, or a piece of 14-inch board should be let into 
the top of three or four joist and the anchor spiked to it. 

Any of these forms of anchors have the objection that in case the 
beams fall during a severe fire or from any other cause they are apt 
to pull the wall over with them. To overcome this objection, as well 
as to secure other advantages, the Duplex Wall Hanger, shown in 
Fig. 144, and the Goetz Box Anchor, shown in Fig. 145, have been 





Fig. 142. 


BRICKWORK. , 219 


iwrented. These devices hold the timber by means of a rib or lug 
gained into its lower edge.’ The anchoring is not as efficient per- 
hans as is secured by the anchors shown in Fig. 142 but is ample 
for cli ordinary corditions, especially as 
when these devices are used every joist 
is anchored. 

These devices also cfer the additional 


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U foB-gZEA+. 
Gi 


Vili 








\ 





Fig. 143. 


advantages that they do not weaken the wall, while they increase the 
bearing of the timbers and reduce the possibility of dry rot to a min- 
imum. ‘They also permit of easily replacing the joist after a fire. 
The Duplex Wall Hanger is especially desirable for party and par- 
tition walls, as it obviates the necessity of building the beams into 





Fig. 144. ; Fig. 145. 


the wall and permits the wall to be as solid at the floor levels as in 
other portions. (See Fig. 146.) 

The importance of anchoring the joist to the walls, and thus pre- 
venting the walls from being thrown outward either from settlement 
in the foundation or from pressure exerted against the inside of the 
wall, is very great, and should not be overlooked by the architect. 
Many walls have either fallen, or had to be rebuilt, that might have 
been saved by proper anchoring. 


720 BUILDING CONSTRUCTION. 


248. Corbeling the Wall for Floor Joist.—In some local- 
ities it is the custom to form a ledge to support the floor joist by 
means of a continuous corbel of three or more courses. ‘This is done 
to prevent weaking the wall by the ends of the floor timbers, for, of 
course, wherever wooden tim- 
bers are built into a wall they 
lessen the section or bearing 


awn anes area of the wall by just the 
: amount of space taken up by 
1{\ the timbers, and in partition 


ay leita walls this is very considerable. 

The Chicago Building Ordi- 

nance provides that all walls 

of warehouses, 16 inches or 

less in thickness, and all walls 

of dwellings, 12 inches or less in thickness, shall have ledges 4 inches 

wide to support the floor joist, and in all cases where ledges are built 
they are to be carried to the top of the joist, as shown in Fig. 147. 

When walls are corbeled in this way it requires a plaster or wooden 

cornice, as shown by the dotted line, to give a proper finish for the 

angles of the rooms, and for this 

reason corbeling is not usually 

done where not required by law. 
















Bl 
t 








ES 
Ht 
Le 





Fig. 146. 


Corbeling for floor joist should 
not be attempted with soft or 
poor bricks. 


249. Walls to be Carried 
Up Evenly.—The walls of a 
building should be carried up 
evenly, no part being allowed to 
be carried up more than 3 feet 
above the rest, except where it is 
stopped by an opening. Build- 
ing one part of a wall up ahead 
of the rest produces unequal settlement, and, the joints in the 
higher part setting before the rest is added to it, the work laid last is 
apt to settle away from the other and weaken the wall, besides mar- 
ring the appearance of it. Whenever it is necessary to carry one part 
of a wall higher than the rest the end of the high part should be 
stepped or racked back, and not run up verticaily, with Boy tooth- 
ings left for connecting the rest of the work. | 





PRLUAVY OF. Z2i 


250. Bonding of Walls at Angles.—An important feature in 
the construction of brick buildings is the secure bonding of the front 
and rear walls to side or partition walls. When practicable both walls 
should be carried up together, so that each course of brick may be well 
bonded. If to avoid delay the side wall must be built up ahead of the 
front wall, the end of the side wall should be built with toothings, as 
shown in Fig. 148, eight or nine courses high, into which the backing 
of the front wall should be bonded. In addition to the brick bonding 
anchors made of 3x2-inch wrought iron, with one end turned up 2 inches 
and the other welded around a 8-inch round bar, should be built into 
the side wall about every 5 feet in height, as 
shown in the figure. The anchors should be 
of such length that the rod will be at least 8 
inches in from the back of the front wall 
and extend at least 17 inches into the side 
wall. The building regulations of most of 


cC the larger cities require that all intersecting 
S brick walls shall be tied together in this way. 
Si 251. Openings in Walls.—The loca- 
2 tion of all door and window openings in 
fn brick walls should be carefully considered, 
oe not only as regards convenience, but also as 
oO! ; 

af to their effect on the strength of the wall. 
a The combined width of the openings in any 
Fey bearing wall should not much exceed one- 





fourth of the length of the wall, and as far 
as possible the openings in the different 
stories should be over each other. Especially avoid placing a win- 
dow either under a pier or directly over a narrow mullion, as at @ or 
6, Fig. 149. If windows must be used in these positions, steel beams 
should be placed over the windows a and ¢, as a stone lintel or brick 
arch would be quite sure to crack from the combined effects of the 
load and the settlement of the joints in the brickwork on either side 
of the window. | 

All openings in exterior walls should either have relieving arches 
or cast iron or steel beams behind the stone cap or face arches. 
Ordinary relieving arches (see Section 265) are commonly used 
where the width of the opening is less than 6 feel, and steel beams 
for greater widths. In bearing walls, where the top of the openings 
come within 12 inches of the bottom of the floor joist, it is hardly 
safe to use relieving arches, unless the floor loads are very light. 


Fig. 148. 


222 BUILDING CONSTRUCTION. 


For door openings in unplastered brick partitions cast iron lintels 
may be used to good advantage, as they give a smooth, level soffit to 
the opening and show only a narrow strip of metal on the face of the 
wall. 

252. Joining New Walls to Old.—When a new wall is to be 
joined to an old one, at right angles, a 
groove should be cut in the old wall sim- 
ilar to that shown in Fig. 118 for the new 
wall to fit into and to allow of its settling 
independently. A cheaper method, and. 
one more commonly used in lhght work, 

Is to nail a scantling, or 2x4, to the wall 
of the old building, so that it will come 
in the centre of the new wall, as shown in 
Fig. 150. <A similar method can be used 
for jointing the ends of an old and new 
wall. New work should never be toothed 

clic] to old work unless the new work is laid in 
cement. 


<1 253. Thickness of Walls.—There 

sien; is no practical rule by which it is possible 

to calculate the necessary thickness of Erick walls, as the resistance 

to crushing, which is the only direct strain, is usually only a minor 
consideration. 

We must therefore rely principally upon experience in determin- 
ing the thickness of walls for any given 
building, unless the construction of the 
building is controlled by municipal or 
State regulations. 





In nearly all of the larger cities of the 
country the minimum thickness of the 
walls is prescribed by law or ordinance, 
and as these requirements are generally 
ample they are usually adhered to by archi- 
tects when designing brick buildings. | 

Table IX. gives a comparison of the 
thickness of walls required for mercantile buildings in the repre- 
sentative cities of the different sections of the United States, and 
affords about as good a guide as any to the young architect. Walls 
for dwellings are generally permitted to be 4 zuches less thanthe 
thicknesses given in the table. 





Fig. 150. 


BRICKWORK. 


223 


TABLE 1X.—THICKNESS OF WALLS IN INCHES FOR WAREHOUSES, ETC, 











HEIGHT 
OF BUILDING. 





Two Stories. 


Three Stories. 


Four Stories. | 


Five Stories. 


Six Stories. 


Seven Stories. 


Eight Stories. 


Nine Stories. 


Ten Stories. 





Boston . 

ew York . 
Chicago .. 
Minneapolis 
Memphis. . 
Denver .. 


Boston . . 

ew York . 
Chicago .-. 
Minneapolis 
Memphis 
Denver... . 


Boston .”*. . 
New York . 
Chicago .. 
Minneapolis 
Memphis. . 
Denver... 


Boston . . 
New York . 
Chicago . . 
Minneapolis 
Memphis. . 
Denver 


Boston.. . 

New York . 
Chicago .. 
Minneapolis 
Memphis. . 
Denver... 


Boston. . 

New York . 
Chicago <*. 
Minneapolis 
Memphis. . 
DCnVers mcr 


Boston... 
New York . 
Chicago .. 
Minneapolis 
Memphis. . 
Denver. . 


Boston... 
New York . 
Chicago .. 
Minneapolis 
Memphis. . 
Denver in. 


Boston... 
New York . 
Chicago .. 
Minneapolis 
Memphis. . 
Denver.”>).; 


Ist | 2a 


Aehite 


12 
Iz 
12 
18 
13 


+ |20 


16 
16 
16 


. (224 


17 


20 
16 
20 
16 
27 
21 


54 
30 


12 
12 
12 
12 
i 
13 


16 
16 
12 
12 
18 


3d | 4th | stn | 6th | 7th | 8th | 9th [10 


16 
12 
12 
12 
13 
13 


16 


16 
12 
18 
13 


20 
16 
16 
16 
224 


17 


20 
20 
20 
16 
27 


21 


20 
24 
20 
20 


16 
12 
12 
12 
13 
13 


20 
16 
16 
12 
18 


17 


20 
20 
16 
16 
224 


17 


20 
20 
20 
16 


314)27 


21 


20 
24 
20 
20 


2I 


24 
28 
24 


21 


403/36 
26 |21 


STORIES. 


20 |16 
16 |16 
16 |16 
16 j12 
18 |13 
7 iTS 


20 |20 |16 
20 |16 |16 
16 |16 |16 
16 |16 |12 
228/18 [13 
EFT Ey 


20 |20 |20 
20 |20 |16 
20 116 |16 
16 |16 |16 
224118 
21 |17 |17 


20 |20 |20 
24 |20 |20 
20 |20 |16 
20 {16 |16 
313/27 
21 |21 |17 


20 |20 |20 
24 |24 |20 
24 |20 |20 
20 |20 |16 
314)27 
21 |21 





llth |12th 


$e.) a a) Tele 
° e s ® e ° 


eortteccsleve 


serleos 


*@eleece 


224 BUILDING CONSTRUCTION. 


In compiling this table the top of the second floor was taken at 19 
feet above the sidewalk, and the height of the other stories at «3 feet 
4 inches, including the thickness of the floor, as the New York and 
Boston laws give the height of the walls in feet instead of in stories. 
When the height of stories exceeds these measurements the thickness 
of the walls in some cases will have to be increased. 


The maximum height of stories permitted by the Chicago ordi- 
nance with these thicknesses of walls is 18 feet in first story, 15 feet 
in second story, 13 feet 6 inches in the third and 12 feet in the stories 
above. 


Although there is a great difference in the thicknesses given in the 
table, more indeed than there should be, yet a general rule might be 
deduced from the table, for mercantile buildings over four stories in 
height, which would be somewhat as follows: 


For brick equal to those used in Boston or Chicago make the 
thickness of the three upper stories 16 inches, of the next three below 
20 inches, the next three 24 inches and the next three 28 inches. 
For a poorer quality of material make only the ¢wo upper stories 16 
inches thick, the next three 20 inches and so on down. 


In buildings less than five stories in height the top story ae be 
12 inches in thickness. 


For the walls of dwellings, 13 inches and g inches may be used for 
two-story buildings ; for three-story buildings the walls should be 13 
inches thick the entire height above the basement, and for four-story 
buildings 17 inches in first story and 13 inches the entire height 
above. , 

In determining the thickness of walls the following general prin- 
ciples should be recognized : 

First. That walls of warehouses and mercantile buildings should 
be heavier than those used for living or office purposes. 

Second. That high stories and clear spans exceeding 25 feet 
require thicker walls. 

Third. That the length of the wall is a source of weakness, and 
that the thickness should be increased 4 inches for every 25 feet over 
Ioo or 125 feet,in length. (In New York the thicknesses in the 
table must be increased for buildings exceeding 105 feet in depth. 
In the Western cities the tables are compiled for warehouses 125 feet 
in depth, as that is the usual depth of lots in those cities.) 

Fourth. That walls containing over 33 per cent. of openings should 
be increased in thickness. 


BRICKWORK. 228 


Fifth. Partition walls may be 4 inches less in thickness than the out- 
side. walls if not over 60 feet long, but no partition to be less than 8 


inches thick. 
PARTY WALLS. 


There is much diversity in building regulations regarding the 
thickness of party walls, although they all agree in that such walls 
should never be less than 12 inches thick. About one-half of the 
laws require the party walls to be of the same thickness as external 
walls ; the remainder are about equally divided between making the 
party walls 4 inches thicker or thinner than for independent side 
walls. 

When the walls are proportioned by the rule previously given, the 
author Lelieves that the thickness of the party walls should be 
increased 4 inches in each story. The floor load on party walls is 
obviously twice that on side walls, and the necessity for thorough 
fire protection is greater in the case of party walls than in other walls. 

254. Curtain Walls.—In buildings of the skeleton type the 
outer masonry walls are usually supported either in every story or 
every other story by the steel framework, and carry nothing but 
their own weight. Such walls may, therefore, be considered as only 
one or two stories high, and are usually made only 12 inches thick 
for the whole height of a twelve or fifteen-story building. 


255. Wood in Walls.—As a rule, no more woodwork should 
be placed in a brick wall than is absolutely necessary. Wooden lin- 
tels for supporting brick walls are objectionable not only on account 
of their being combustible, but also on account of their shrinkage. 
It is generally impossible to obtain framing lumber that is thor- 
oughly dry, and when a brick wall is partially supported by a wooden 
lintel a crack is quite sure to develop sooner or later in the manner 
shown in Fig. 151. The crack is obviously caused by the shrinkage 
of the lintel, which permits the portion of the wall supported on it to 
settle by an amount equal to the shrinkage of the wood, while the 
portion of the wall a, being supported on the brick pier, does not 
pesettle: 

Bond timbers, or pieces of studding laid under the ends of the floor 
joist, are also objectionable, for the reason that they are quite sure 
to shrink, and thus leave the wall above them unsupported. Bond 
timbers are very convenient for the carpenters, as they give a level 
bearing for the floor joist, and they also distribute the weight over 
the brickwork, but they should never be used in buildings over two 


206 BUILDING CONSTRUCTION. 


stories in height, or in walls less than 12 inches thick. If used at all 
they should be selected from the dryest lumber that can be obtained. 

For the proper use of wooden lintels under relieving arches see 
Section 265. 

Strips of wood are sometimes built into. walls to form a nailing for 
the wood finish or for the furring strips. Such strips should not be 
used in buildings over two stories in height, and should not be over 
2 inch thick, so that they may take the place of the mortar joint. 

Wooden bricks, or blocks of wood of the size of a brick, are also 
sometimes built into brick walls to provide nailings for furring strips, 
door frames, etc. These not only tend to weaken the wall, but they 
generally shrink so as to become loose, thereby losing their holding 
power. If the bricks are so hard that nails cannot be driven into 
them, and the mortar is too poor to hold the nails, then porous terra 
cotta blocks should be used for nailing strips in first-class work. 

Porous terra cotta will hold a nail almost like a board, and has 
none of the objections common to wood. 





Fig. 151. Fig. 152. 


256. Cracks in Walls.—lIt is a very common thing to see 
cracks in brick walls. ‘These cracks may be produced by either one 
of several causes. ; 

Probably the most frequent cause of the cracking of masonry walls 
is the settlement of the foundations, either from their being improp- 
erly designed or from the settlement of the ground caused by wet. 
A strict observance of the principles laid down in Sections 24, 29 
and 30 will generally prevent cracks starting from the foundation. 

The effect produced on certain soils when they become saturated 
with water is described in Section 9. 

Next to faulty foundations, the most common cause of cracks in 
brick walls is probably the use of wooden lintels, as described in Sec: 
tion 255. 


oe 


BRICKWORK. 227 


Besides the cracks that occur from these causes, cracks often occur 
over openings from settlement of the mortar joints in the piers or 
from spreading of the arches. 

It is very common to see a small crack just above the end of a 
door or window sill, as shown in Fig. 152. Such cracks generally 
occur near the bottom of high walls, and are caused by the compres- 
sion of the mortar in the lower joints of the pier. They may be 
avoided by using slip sills, as described in Section 191. 

Another place where cracks produced by the settiement of mortar 
joints sometimes occur is where a low wall joins a very high one. To 
prevent such cracks the walls should be joined by a slip joint, as de- 
scribed in Section 206. 

Generally cracks are more likely to occur in walls that are broken 
by frequent openings than in a plain, unbroken wall. 

The use of plenty of anchors and thorough bonding will do much 
toward preventing cracks. 

257. Damp-proof Courses.—When buildings are built on 
ground that is continually moist or wet the moisture is very apt to 
soak up into the walls from the foundations, rendering the building 
unhealthy and often causing the woodwork to rot. ‘To prevent the 
moisture rising in this way a horizontal damp-proof course should be 
inserted in all walls below the level of the first floor joist. It should 
be at least 6 inches above the highest level of the soil touching any 
part of the outer walls, and should run unbroken all around them 
and at least 2 feet into all the cross walls; and on very wet ground, 
where the water is but a few feet below the surface, it should be con- 
tinuous through all the walls. In buildings finished with parapet 
walls it is also desirable to insert a damp-proof course just above the 
flashing of the rcof or gutter to prevent the wet from soaking down 
into the woodwork of the roof and into the walls below. 

Materials —These damp-proof courses may be formed of either of 
the following materials : ; 

A sphalt.—A layer of rock asphalt 3 of an inch thick makes the best 
damp-proof course, and should be used for all first-class buildings. 
_ The surface to receive the hot asphalt should be quite dry and should 
be made smooth to economize material, and all the joints should 
be well flushed up with mortar. The best asphalts for this purpose 
are the natural rock asphalt from Seyssel, Val de Travers or Ragusa, 
which are imported into this country in the shape of blocks and 
cakes. When used the cakes are melted in large kettles, mixed with 
a small proportion of coal tar and applied hot. One or two layers of 


228 BOULLDING CONSTRUCTION: 


tarred felt imbedded in the hot asphalt may also be used with good 
results. 

“ Roofing slates, or even hard vitrified bricks, two courses break- 
ing joint, laid in half cement and sand mortar, or such bricks laid 
without any mortar in the vertical joints, form an inexpensive damp 
course.” Glass is also sometimes used for this purpose. 

Portland Cement.—A 4-inch layer of Portland cement mortar, 
mixed in the proportion of 1 part cement and 1 of sand, will often 
answer the purpose, but is not as desirable as the materials mentioned 


above. 
HOLLOW WALLS: 


258. Their Object.—lIt is well known that a solid brick wall 
readily absorbs moisture and transmits heat and cold. A driving 
rainstorm will often penetrate a 12-inch brick wall so as to dampen 
the wall paper or spoil the fresco decorations. It is also known that 
a house with damp walls is unhealthy and a frequent cause of rheu- 
matism ; besides this the moisture in the brickwork prevents the mor- 
tar, if made of lime, from becoming hard, and is also liable to com- 
municate itself to the woodwork, thereby causing rot. 


A building with damp walls will also require the consumption of 
very much more coal in warming than one with dry walls, as the 
moisture must be evaporated before the temperature of the walls can 
be raised. 

To overcome these objections to a solid brick wall, particularly in 
residences and school. houses, hollow or vaulted walls have been 
much used, and are earnestly recommended by various persons. 


Theoretically, a hollow wall should prevent the passage of moist- 
ure through the wall, and by providing an air space in the wall, make 
the building much cooler in summer and warmer in winter. 


In the actual construction of the walls, however, there are certain 
difficulties met with, which, to a considerable extent, offset the advan- 
tages, so that hollow walls are comparatively little used in this 
country. 

The author believes, however, that their use might be much 
extended with beneficial results, especially for isolated buildings. 


To obtain the full benefit of an air space it should be continuous 
throughout the wall, and the bond or connection between the two 
parts of the wall should be of such material and of such a shape that 
the moisture which penetrates the outer portion cannot be conveyed 
to the inner portion. 


% 


BRICKWORK. 229 





ete iS LS NS 
SEAENRSN NC Rel’ ch 


3 “ONS x 





























Sins 
SS 


more commonly placed 
SS on the outside of the 
SS AAA wall, but this necessitates 


> hs 


Fig. 153. 


RS 
S 


RRR 
RRS rived from it. 
SS 








To provide a continuous air 
space in a wall penetrated by 
openings is practically impossi- 
ble, although it may be quite 
closely approximated. 

The objections commonly 
urged against the vaulted wall 
are increased cost and increase 
of ground area, the latter being 
an important consideration in 
city buildings. 

259. Methods of Con- 
struction.—There are several 
ways of constructing vaulted 
walls; these differ principally 
in the method of bonding and 
in the thickness of the inner 
and outer portions of the wall. 

Generally, at least one por- 
tion of the wall must be made 8 
inches thick to sustain the 
weight of the floors, the other 
portion being only 4 inches 
thick. Probably the thicker 

portion of the wall is 


extending the floor joist 
through the airspace, and 
thus to a great extent neu- 
tralizing the benefits de- 
By this 
method the thicker por- 
tion of the wall is still 
subjected to the injuri- 
ous effects of the moist- 
ure. 

For two-story build- 


ings the author recommends that the walls be constructed as shown 


in Fig. 153. 


If the wall plate comes above the attic joist the latter 


230 BOULLDING, CONS LTEOCLLION. 


may be supported on the 4-inch wall if well built of good hard brick. 
If the brick are not of very good quality the 8-inch wall should be 
continued to the upper joist. 

When the bricks, mortar and workmanship are of the best quality 
there is no reason why this construction should not answer for even 
four or five-story buildings (if used only for dwelling or lodging pur- 
poses) by making the inner portion 8 inches thick the full height 
and increasing the width of the air space to 6 inches. 

For warehouses the bearing wall in the lower stories should be 
increased in thickness. 

A hollow wall of a given number of bricks securely bonded is much 
more stable than a solid wall of the same number of bricks, and will 
also withstand fire better. It requires much better workmanship, 
however, than is generally bestowed on solid walls, and the mortar, 
particularly in the outer portion, must be of the best quality, and 
preferably of cement. 

Nearly all building regulations require that at least the same quan- 
tity of brick shall be used in the construction of a hollow wall as 
would be used if the wall were built solid, and many of them require 
that both portions of the wall shall be at least 8 inches thick if the 
wall is used as a bearing wall. 

For heavy buildings, with steel floor joist and girders, it is better 
to build the outer wall of the full thickness that would be required 
of a single wall, and to make the inner wall only 4 inches in thick- 
ness, to serve merely as a furring and to receive the plaster. Where 
fireproof arches are used for the floors this inner wall might without 
injury rest on the floor arches. 

260. Bonding of Hollow Walls.—To secure proper strength 
in the wall it is necessary that the two portions of the wall shall be 
well bonded together, so that neither may buckle or get out of plumb. 
Until within a few years this bonding was usually accomplished by 
placing brick headers across the air space, with the ends slightly 
built into the two portions of the wall, as shown at a, Fig. 154. 

Brick bonding, however neutralizes much of the benefit gained by 
the air space, as it permits of the passage of moisture through the 
wall wherever it is bonded. The moisture not only passes through 
the bond bricks, but also through the mortar droppings that invari- 
ably collect upon them. 

The best method of bonding, and the only one which retains the 
full benefits of the air space, is by means of metal ties provided with 
a drip in the centre. Either of the metal ties shown in Fig. 154 may 


BRICK WORK. 231 


be used. That shown at 4 is the “‘ Morse” tie, which is made of 
different sizes of galvanized steel wire and from 7 to 16 inches in 
iength. ‘The other ties are not patented, and may be made by any 
blacksmith. 


That shown at ¢ is probably the best shape where both walls are 8 
inches thick, as it gets a firm hold on the walls and is also much 
stiffer than the wire tie. The iron ties should either be galvanized 
or dipped in hot asphalt or coal tar. 

If either of the ties J, ¢ or @ are used they 
should be spaced every 24 inches in every 
fourth course. ‘The tie e, being stronger, need 
be used only in every ezghth course. 

261. Construction Around Openings. 
—Wherever door or window openings occur 
in hollow walls it is necessary to build the 
wall solid for 8 inches at each side of the 
opening, and also to carry the relieving arch 
entirely through the wall. It is almost impos- 
sible to prevent some moisture passing 
through the wall at these points, but much 
may be done by covering the top of the 
relieving arch with hot tar and laying the con- 
necting brickwork in cement mortar. The 
top of the relieving arch is obviously the 
most vulnerable point, and should. be pro: 
tected in some way and kept as free as possi- 
ble from mortar droppings. 

Ventilation of Air Space.—There seems to be some differ- 
ence of opinion as to whether or not the air space sbould be con- 
nected with the outer air. American writers, however, appear to be 
generally of the opinion that the air space should be ventilated to 
carry off the moisture that collects on the inside of the outer portion 
of the wall. 








Fig. 154. 


It is recommended that the bottom of the air space be ventilated 
through openings into the cellar, and that openings be left in the inner | 
portion of the wall just under the coping of a parapet wall, or above 
the attic floor joist if the wall is covered by the roof. If the air 
space cannot be ventilated into the attic, then ventilation flues should 
be carried up and topped out like a chimney, or built in connection 
with a chimney. It is also recommended that a U-shaped drain tile 


232 BULL DIN GCONSTRECT LON: 


be laid at the bottom of the air space to collect any moisture that 
may run down the outer wall. 


262. Hollow Walls with Brick Withes.—Brick walls are 
sometimes built with a 4-inch inner and outer facing connected with 
solid brick withes, as shown in Fig. 155, the air space being made 4, 
8 or 12 inches, according to the height and character of the build- 
ing. Congress Hall, Saratoga, N. Y., a portion of which is seven 
stories high, is built in the manner shown in Fig. 155, and has stood 





Fig. 155. 


successfully. If such a wall is built of the quality of brick generally 
made in the New England States, and with perfect workmanship, it 
should have ample strength for any ordinary three or four-story 
building, and would certainly be more stable and conduct less heat 
and moisture from and into the building than a solid wall of one- 
half more bricks. With such bricks and workmanship as are com- 
monly found in many portions of the country, however, walls built 
in this way should never be used for any building larger than a two- 
story dwelling. Theoretically, the inside of the wall opposite the 
withes would be subject to dampness, but, of course, not to as great 
an extent as with the solid wall. 


BRICKWORK. 233 


For two-story dwellings, this wall, if well constructed and the 
withes secure!y bonded to the facings, should make a much more 
healthy and comfortable building than the solid wall. 

263. Furring Blocks.—For office buildings furring blocks 
designed for that especial purpose are often used for lining or furring 
the external walls, and sometimes hollow bricks are used for the inner 
4 inches of a solid wall, but the latter have not proved a success in 
excluding moisture. The objection to any kind of furring and to 
hollow brick is that there must necessarily be some connection 
between the mazerza/ of the lining or furring and the wall, and this 
connection allows of the passage of heat and moisture. 

204. Brick Veneer Construction.—It is quite common in 
many sections of the country to budd dwellings, and even three and 





SN 






——> 





SS 


<> 


—— 






ENCES 


IZ 








Fig. 156. 


four-story buildings, with the outer walls of frame construction and 
then to veneer the frame with a 4-inch facing of brick. Buildings 
built in this way have the same appearance, bcth externally and 
internally, as if the wails were entirely of brick. 

Where lumber is cheap and brickwork comparatively expensive 
this method of construction possesses some advantages, although it 
is not generally approved by architects, and should only be used 
where a hollow brick wall cannot be afforded. The advantages pos- 
sessed by a brick-veneered frame wall over a solid brick wall 
are that it costs less and the air spaces prevent any possibility of the 
passage of moisture, and also makes the house much warmer in win- 
ter and cooler in summer. 

About the only advantage that it possesses over a well-built frame 
building is that it reduces the insurance rate, as the veneer offers 
some protection from fire in adjoining buildings. A veneered build- 


234 BUILDING CONST ROGGTION | 


ing, however, is not near as safe from fire as a brick building, and 
would probably be destroyed by fire on the inside about as rapidly as 
though the frame were covered with siding or shingles. 


The only differences in the planning of a veneered building from 
that of a frame building are that the walls are 5 inches thicker, the 
foundations must project sufficiently beyond the frame to support 
the veneer, and the elevations are drawn 
the same as for a brick building. 

The wooden frame should be con- 
structed in the best. manner, with at 
least 4x6 sills, 4x8 posts, 4x6 girts and 
4x4 plates, and be well braced at the 
angles., After the frame is up it should 
be sheathed diagonally and then covered 
with tarred felt. 








It is also very impor- 
tant that the framing 
timber shall be as dry as 
possible, particularly the 
sill and girts, and the 
frame must be perfectly 
plumb and straight. 

The veneer is usually 
laid with pressed or face 
brick, with plumb bond, 
which should be tied to 
’ the wooden wall with 
metal ties. The Morse 
tie, shown ata, Fig. 156, 
is probably the best for 
this purpose, although the author-has used the tie shown at 4 with 
very satisfactory results. The ties should be placed on every other 
brick in every fifth course. | 


Fig. 157. 


In laying out the wall on the floor plans 6 inches should be allowed 
from the outside of the studding to the face of the wall. This gives 
an air space of about 1 inch between the brick and sheathing and 
avoids chipping the bricks where the wooden wall is a little full. It 
is a good idea to build a 2-inch U-shaped drain tile in the founda- 
tion wall under the air space to collect any moisture that may pene- 
trate the veneer. The air space should also be ventilated at the bot- 
tom through 2-1nch drain tile, as shown in Fig. 157. 


\ 


BRICK WORK. 235 


The top of the brickwork generally terminates under the eaves or 
gable finish. If the building has a flat roof, with parapet walls, the 
latter should be coped with either copper or galvanized iron and 
tinned on the back down to the flashing. 

Fig. 157 shows a partial section through the foundation and a por- 
tion of the first story wall of a veneered dwelling to illustrate the 
construction described above. 


DETAILS OF CONSTRUCTION IN BRICKWORK. 


265. Brick Arches.—Brick arches are generally used for span- 
ning the openings in brick walls, and where there is sufficient height 
for the arch they form the most durable support for the wall above. 
The arches should be laid with great care with full joints, and all 






Some 
ESSSS 
DSS 

Bees 
Peau 
PEERS 
cueacgoaeaen 
vagiareaci 









Fig. 158. Fig. 159. 


arches. having a span of over to feet should be taid in strong cement 
mortar, and it is much safer to lay all brick arches in cement. 
Gauged Arches—When arches are built of common brick the 
bricks are laid close together on the inner edge, with wedge-shaped 
joints, as shown in Fig. 161, but when built of face bricks the arch 
rim is laid out on a floor and each brick is cut and rubbed to fit 
exactly the place chosen for it, so that the radial joints are of the 
same thickness throughout. Such work is called gauged work. 
Bond.—The only point requiring especial mention in connection 
with brick arches is the bond. When gauged arches are used the 
bricks are generally bonded on the face of the arch to correspond 
with the face of the wall, as shown in Fig. 158. Such an arch is 
called a bonded arch. Bonded gauged work makes the neatest and 
strongest job, but it is too expensive for common brick arches. 
Arches of common brick are generally built in concentric rings, 
either without connection with each other, except by the tenacity of 


236 BUILDING CONSE CCLOLS. 


the mortar, or else bonded every few feet with bonding courses built 
in at intervals like voussoirs, as shown by the heavy lines at 4, 
Fig. 160. When the concentric rings are all headers, as in Fig. 159, 
the arch is designated:as a rowdlock arch, or bond, and when built 
with bonding courses, as in Fig. 160, it is known as block i” course 
bond. Segmental arches are 
often built with concentric 
rings of stretchers (Fig. 161), 
which may be bonded at right 
angles to the face by hoop iron. 
When the radius is over 15 feet 
this should be stronger than 
the rowlock bond. 

Common brick arches are 
sometimes bonded by introduc- 
ing headers so as to unite two 
half brick rings wherever the 
joints of two such rings happen to coincide. Fig. 162 shows the 
bonding employed in arching the Vosburg tunnel on the Lehigh Val- 
ley Railroad, the span being 28 feet. Building an arch in concentric 
rings has the objection that each ring acts nearly or quite independ- 
ent of the other, and the least settlement in the outer rings throws 
the entire pressure on the inner 
ring, which may not be able to 
resist it. When bonding courses 
are used, however, they serve to - 
tie the rings together and to dis- 
tribute the pressure between them, 
so that the above objection is 
overcome. For arches of wide 





Fig. 160. 


span, or when heavily loaded, 
some form of block in course bond 
should be used. Hoop iron is often 
built into arch rings parallel to the soffit, and is also often worked in 
the radial joints to unite the different rings. The stability of an arch 
‘may be greatly increased by its use. 





. Skewback.—In building brick arches of large span it is important 
to have a solid bearing for the arch to spring from. Such a bearing 
may be best obtained by using a stone skewback, as shown in 
Figs. 161 and 162. ‘The stone should be cut so as to bond into 
the brickwork of the pier, and the springing surface should be cut to 


BRICKWORK. 237 


a true plane, radiating to the centre from which the arch is struck. 
For large arches the skewbacks should be bedded in cement. 


Flat Arches.—¥ lat arches are often built over door or window 
openings in external walls for architectural effect. Such arches, if 
built with a perfectly level soffit, 
almost always settle a little, and it is 
better to give a slight curve to the 
soffit, as in Fig. 163, or else support 
the soffit of the arch on an angle bar, 
the vertical flange of the bar being 
concealed behind the arch. 


Relieving Arches.—The portion of 
a wall back of the face brick arch, or 
stone lintel over door or window 
openings, should be supported by a 
rough brick arch, as shown in 
Fig. 164. A wooden lintel is first put 
across the opening, and on this a 
brick core or centre is built for turn- 
ing the arch. Sometimes arched wooden lintels are used and the 
arch turned on them. When the walls are plastered without furring 
the method shown in the figure is the best, as there will be less wood- 
work. The lintel should not have a bearing on the wall of more than 
4 inches, and the arch should spring from beyond the end of the lin- 


cE? 





Fig. 162. 













































Fig. 163. Fig. 164. 


tel as at A, and wot as at B, as in the latter method the arch is 
affected by the shrinkage of the lintel. 


266. Vaults.—Brick vaults are usually constructed in the same 
way as common brick arches, except that the bricks should be 
bonded lengthwise of the vault. 


238 - BUILDING CON STROCTLION: 


Cross, or groined vaults, are generally supported at the inter- 
sections by diagonal arches of the proper curvature, built so as to 
drop 8 or 12 inches below the soffit of the vault. 

Vaults may be economically constructed by a combination of 
brickwork and concrete, or even entirely of concrete. When built 
entirely of concrete, however, very strong centres are required. 

Fig. 165 * shows a method of constructing vaults much used by 
the ancient Romans. A light temporary centre of wood was first 
put in place, and on this light brick arches were built to form a 
framework for supporting the weight of the vault until set. These 

















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Fig. 165. 


brick arches were called armatures, and as they became the real sup- 
port of the vault only very light wooden centres were required. 
After the armatures were built the spaces between them were filled 
with rough masonry or concrete, as shown in Fig. 166. 

267. Chimneys.—In planning brick chimneys: the principal 
points to be considered are the number, arrangement and size of the 
flues and tne height of the chimney. Every fireplace should have a 
separate flue extending to the top of the chimney. Two or three 
stoves, however, may be connected with one flue if it is of sufficient 
size, and the kitchen-range may be connected with the furnace flue 
without bad results, and often the draught of the furnace will be ben- 
efited thereby. For ordinary stoves and for a small furnace an 8x8 


* Figs. 165 and 166 are taken from the Brickbuzlder, by permission. 


BRICKWORK. 239 


flue is sufficiently large if plastered smooth on the inside, but it is 
generally better to make the furnace flues 8xr2 inches and also the 
fireplace flues, except for very small grates. 

The best smoke flue is one built of brick and lined with fire clay 
tile, or else a galvanized iron pipe supported in the middle of a large 
brick flue. When the latter arrangement is used the space surround- 
ing the smoke pipe may be used for ventilating the adjoining rooms 
by siraply putting registers in the wall of the flue. 

When galvanized iron smoke pipes are used the metal should be at 
least of No. 20 gauge, and No. 16 gauge for boiler flues. Even then 





Fig. 166. 


the pipe is liable to be eaten away by rust or acids within ten or 
twelve years. Fire clay flue lining, on the other hand, is imperishable. 

Smoke flues are sometimes made only 4 inches wide. Such flues 
may work satisfactorily at first, but they soon get clogged with soot 
and fail to draw well, and should never be used unless it is imprac- 
ticable to make the width greater. | 

More flues smoke or draw poorly on account of the chimney not 
being of sufficient height than from any other cause. A chimney 
should always extend a little above the highest point of the build- 
ing or those adjacent to it, as otherwise eddies may be formed by 
the wind which may cause a downward draught in the flue and 
make it smoke. If it is impracticable to carry the chimney above 
the highest point of the roof it should be topped out with a hood, 


240 BUILDING GON STROCTICN, 


open on two sides, the sides parallel to the roof being closed. Thé 
walls and wéthes (or partitions) of a chimney should be built with 
great care, and the joints carefully filled with mortar and the flues 
plastered smooth on the inside with Portland cement, both to pre- 
vent sparks or air from passing through the walls and to increase the 











Vertical Section. 


Fig. 167.—Plan. 


stp 


draught. Chimneys were formerly 
plastered with a mixture of cowdung 
and lime mortar, which was called 
pargetting, but this mixture is now sel- 
dom, if ever, used. Portland cement 
is not affected by heat and is the best 
material for this purpose. 

In building the chimney more or 
less mortar and pieces of brick are sure 
to drop into the flue, and a hole should 
be left at the bottom, with a board 
stuck in on a slant, to catch the falling 
mortar. After the chimney is topped 
out the board and mortar should be 
removed and the hole bricked up. If 
there are bends in the flue, openings 
should be left in the wall at those 
points for cleaning out any bricks and 
mortar that may lodge there. The 
outer wall of a chimney should be 8 
inches thick, unless a flue lining is 
used, to prevent the smoke being 
chilled too rapidly. 

During the construction of the 
building the architect or superintend- 
ent should be careful to see that no 
woodwork is placed within 1 inch of 
the walls of a flue, and that all the 
flues are smoothly plastered their 
entire height. 


The arrangement of the flues is ordinarily very simple. Fig. 167 
shows the ordinary arrangement of the flues in a chimney containing 
a furnace flue and fireplaces in first and second stories, and ash flue 


for second story fireplace. 


_ Fig. 168, from Part II. of “Notes on Building Construction,” 
shows the arrangement of the flues in a double chimney, with fire- 


places in five stories. 


241 


BRICKWORK. 


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242 BUILDING CONSTROCTION. 


268. Fireplaces.—2ough Cpening.—In building fireplaces, no 
matter how they are to be finished, it is customary first to build a 
rough opening in the chimney from 6 to 8 inches wider than the in- 
tended width of the finished opening, and an inch or two higher, 
drawing in the brick above to form the flue, as shown in Figs. 167 
and 168. The front wall of the chimney over the opening may be 
supported by a segment arch when there is sufficient abutment, but 
when the side walls are but 4 or 8 inches thick, heavy iron bars 
should be used to support the brickwork. The depth of the rough 
opening should be at least 12 inches, to 
















permit of an 8-inch flue. 

The bottom of the chimney, when 
there are fireplaces, is usually built hol- 
low to form a receptacle for the ashes 
from the grate, as shown in Fig. 169. 
If the fireplace is to be used frequently 
an ash pit is almost a necessity, espe- 
cially in residences, and should always 
be provided when practicable. When 
the fireplace is above the ground floor a 
flue can generally be built to connect the 
bottom of the fireplace with the ash pit. 
In the chimney shown by Figs. 167 and 
169 the ash flue is built 
back of the lower fire- 
place. When there is no 
furnace flue the ash flue 
can be carried down at 
one side of the lower fire- 
place, thereby saving 4 
inches in the thickness of 
the ‘chimney, 9 -Oném@ash 
flue will answer for several fireplaces. A cast iron door and frame 
(usually about roxr2 inches) should be built in the bottom of the 
ash pit to permit of removing the ashes. 

The ash pit, rough opening and flues form the chimney, and are 
all built at the same time by the brick mason, who also builds the 
trimmer arch. ) : 

Trimmer Arch.—In buildings with wooden floor construction the 
hearth is usually supported by a “trimmer arch,” commonly 2 feet 
wide by the width of the chimney, turned on a wooden centre from 


Fig. 169. 


ry GA Ol A 242a 


the chimney to the header or trimmer, as shown in Fig. 169. The 
centre is put up by the carpenter, one side being supported by the 
trimmer and the other by a projecting course on the chimney, or by 
flat irons driven into the joints. Although not needed for support 
after the arch has set, the centre is generally left in place to afford a 
nailing for the lath or furring strips on the ceiling below. 

Sometimes a flagstone is hung from the joists to support the hearth, 
but a stone generally costs more than the arch, and in the opinion of 
the author is not as good, as the arch will adjust itself to a slight set- 
tlement in the chimney, and is not affected by shrinkage of the floor 
joists. 

finished Ftreplace.—After the building is plastered the finished 
fireplace is built, usually by the parties furnishing the material, 
unless it is of brick, when the work may be done by any skilled 
brick mason. 

At the present time the larger number of fireplaces are probably 
built with fire brick linings and tile facings and hearths, with wooden 


ByiPartition 



















sem { 4 Plaster 
i; Vy 
“Mantel | He Facing WEL ANMantel 
Chimney Plastered. Chimney Furred 


Fig 1692. 


mantels, after the manner shown by Figs. 169 and 169a. The various 
steps in building such a fireplace are to first level up for the hearth 
with brick or concrete, after which the hearth ana “under fire”’ are 
laid, the metal frame at the edge of the opening set up and the lining 
and the backing for the tile facing built. After this work is com- 
pleted the tile facing is set, and when the mortar has dried out, the 
mantel, if of wood, is set against it. Itis best to use glazed tile for 
the hearth and facings, and they should always be set in rich Port- 
land cement mortar. The sides of the lining or fire box should be 
beveled about 3 inches to the foot, and the back should be brought 
inward at the top, as shown, so that the opening into the flue will be 
only about 3 inches wide. This opening is called the “throat,” and 
its proportions determine in a great measure whether the draught will 
be good or bad. 


2420 BOULLDING CON SIRUCL LOM: 


A damper should always be provided for closing the throat. The 
simplest arrangement is a piece of heavy sheet iron with a ring on 
the edge, as shown at A, Fig. 169, which may be operated by the 
poker. A much better device, and one now quite frequently used, 
consists of a cast iron frame with a door which may be pushed back 
to give the full opening, and the door also has a sliding damper suffi- 
cient to let off the gases after the fire is well started. This device 
can be obtained of most mantel dealers, and generally insures a good 
draught. A small cast iron ash dump should also be placed in the 
bottom of the fireplace when there is an ash pit. 


Grates.—There are a great many styles of grates that may be used 


in fireplaces. In a fireplace such as has been described, the “club 
house”’ grate is probably most frequently used in localities where soft 
coal is burned. It consists of a cast iron grate supported by four 
legs, and with an ornamental front about 6 inches high. It has no 
back or sides, but should fit close to the fire brick hning. There is 

also a movable front to close the opening beneath the grate. Sucha 
- grate works very well for soft coal or coke. 

For fireplaces that are to be frequently or steadily used a narrow 
opening (say 21 inches) is most desirable, as the wider openings are 
very wasteful of coal. 

Fireplaces in which wood is to be burned may have openings up to 
4 feet wide, 3-foot openings being quitecommon. Wood is generally 
burned on andirons. 

For burning hard coal, especially in ornamental fireplaces, basket 
grates having an open front and solid back and ends are often used. 
They are made of various sizes and may be used in any fireplace. 

One of the most practical devices for a fireplace is the portable 
fireplace, which is a complete cast iron fireplace with fire box, damp- 
ers, shaking grate and separate front’ piece for summer. It can be 
set In any opening of suitable size, and is sure to draw well if the flue 
is reasonably large and high. ‘These fireplaces are finished with an 
ornamental frame about 3 inches wide, in different finishes, and can 
be used with either tile, marble or brick facings. They are made 
with 20 and 24-inch openings. 

Brick Fireplaces.—Fireplaces may be built with pressed brick 
facings, with either square or arched openings, and a wool mantel 
set against them, the same as with a tile facing. If wood is to be 
burned pressed brick may also be used for the linings, but they will 
not withstand the intense heat of a coal fire. For a coal fire fire 
brick should be used for the linings. 


BRICKWORK. 242¢ 


Although brick facings in connection with wooden mantels have 
been much used, the practice does not seem to be very desirable, 
either from a practical or decorative standpoint. If brick is to be 
used at all, it seems more desirable to make the whole mantel of brick 
or of brick and terra cotta. In fact there are no materials which can 
be used for finishing about a fireplace with better effect than brick or 


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Fig. 169.—Brick and Terra Cotta Fireplace Mantel. Manufactured by Fiske, Homes & Co. 
J. H. Ritchie, Designer. 
terra cotta, although they require artistic skill in the selection of the 
color and in their arrangement. 

The great drawback in building brick mantels in the past has been 
the difficulty of obtaining bricks of suitable color and accuracy, and 
which can be adapted to a satisfactory decorative treatment. This 
difficulty, however, no Ionger exists, as there are now two or three 


2420 


BUILDING CONSTRUCTION. 


firms that make a specialty of producing brick mantels of a high 


grade of artistic value. 


These mantels are designed by skilled archi- 


tects to produce the highest architectural effect, and all the parts 


— 7 


ZR 








BRICK STAIRS. 
SUPPORTED ONIRON BEAMS. 








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Slate tread 


Baluster 


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LONGITUDINAL SECTION, 


Fig. 169¢.—Details of Biick Stairs, 


are accurately fitted, so that the mantel can be easily built by any 


pressed brick mason. 
colors, and can be varied 
lar space. 


They are made in a variety of designs and 


within certain limits of size to fit a particu- 


The mantels of the Philadelphia and Boston Face Brick 


Co. have been extensively used during the past eight years, and with 


very satisfactory results. 


BRICKWORK. 242¢ 


Messrs. Fiske, Homes & Co., of Boston, have also recently under- 
taken the production of brick and terra cotta mantels of a very high 
degree cf excellence. 

In these mantels the ornamentation is largely in terra cotta instead 
of moulded bricks, and a special feature of this terra cotta ornamen- 
tation is that the pieces are made in standard sizes which are inter- 
changeable. This feature will probably be appreciated and utilized 
by architects, as it affords them the 
opportunity of making designs to suit 
their own individual tastes as regards 
the choice and arrangement of orna- 
mentation, by bringing together in 
any desired combination the standard - 
interchangeable pieces, thus gaining 
practically all the desirable features 
of special designs, with the additional 
advantages of moderate cost and cer- 
tainty of delivery. 

Fig. 1694 illustrates a low-cost de- 
sign in which the facing is made of 
8x14-inch bricks with beaded jambs, 
with a bead and reel border, and the 
cornice of egg and dart and dentil 
design ; a wood shelf and backboard 
are used to give a smooth and finished 
eirect: 

2683. Brick Stairs.—For build- 
Staircase, House of Tristran the Hermit, ing fireproof stairs there is probably 
Tours, France. : ; 

no better material than brick, unless 
it be Portland cemient concrete in combination with metal tension 
bars. Brick stairs may easily be built between two brick walls by 
springing a segment arch from wall to wall to form the soffit and 
building the steps on top of this arch; or, if one side of the stairs 
must be open, that side may be supported by a steel I-beam, as shown 
in Fig. 169¢, which should be protected by fireproof tiling. The 
stairs in the Pension Building at Washington were constructed in 
this way. The treads of the steps may be of hard pressed brick, or 
slate treads may be laid on top of the brick. Iron treads are not de- 
sirable, as they become slippery. 

Brick Spiral Stairs.—Fig. 169¢ shows a method of con- 
structing spiral stairs of brickwork commonly employed in Ma- 


Rp 
. 





242f BUIEDING CONSLTAOCTION a 


dras, India. These stairs are built without any centring, and cost in 
Madras less than one-third as much as iron stairs. It would seem 
as though this construction might be advantageously employed in 
this country where spiral stairs are to be built in fireproof buildings. 
The dimensions of a typical Madras spiral stair are about as follows: 


Diameter of stair, wall to wall, inside............4.. 6 feet. 
Diameter of newel: 1h CENITG: cso oeuncacs nee vieie tarsns I foot. 
Headway, from top of step to arching overhead,.... 7 feet 1} inches. 
Risers, Cach chk ce x stoteten eases tale ee elena cata ees <s 
Treadsat wall’: 2. : ces a uurelcie tes yyieis tare ccetnetolelt taeteteat ta LOOLr 2g ames 
Tread: at iewelse sos cue 500 ore ee Soop oiais <iv.e she ‘eyied is ote Tak 


Having determined the rise and num- 



















SECTION 5 ber of steps in the usual way, work is com- 
ON Chto menced by building up solid two or three 
+ bh steps, when the arch is then started by ordi- 


2_ Lf 
i - § nary terrace bricks, 5x3xI inch, in lime mor- 
all 7) tar (14 parts slaked lime to I of clean river 
sand), The bricks are put edgewise flat 
against one another, with their lengths in 
radii from the centre of the stair, and are 
simply stuck to one another by the aid of 
the mortar without any centring. These 
arch bricks are arranged as shown at 5S, the 
soffit being a continuous incline, as shown 
in the section C D. A slight rise, about 
1} inch, is given to the arch as shown in the 
section. 

For forming the steps over this arching 
ordinary bricks are used, usually 9x43x3 
inches, trimmed to position and placcd on 
edge as at 7’ in the plan, 

After a reasonable time for the mortar 
to harden the work should bear a load of 
300 pounds placed on a step and show no 
sign of giving. With good materials the 
steps will bear much heavier loads.—/. 1/., 
in Indian Engineering. 

Fig. 169d 269. Brick Nogging.—Wog- 

ging is a term that is applied to 

brickwork filled in between the studding of wooden partitions. It is 
often employed in wooden partitions of dwellings and tenement 
houses to obstruct the passage of fire,sound and vermin. As no par- 
ticular weight comes upon the brick, and they are not exposed to 
moisture, the cheapest kind of brick may be used for this purpose. 


BRICKWORK. 243 


The brick should be laid in mortar, as in a 4-inch wall. If the par- 
tition is to be lathed with wooden laths it is necessary that the width 
of the bricks shall not be quite equal to that of the studding, to allow 
for a clinch to the plaster. When 3#-inch studding is used it will be 
necessary either to clip the brick or lay them on edge. 

When the studding of a partition rests on the cap of the partition 
below it is an excellent idea to fill in the space between the floor and 
the ceiling below with nogging to prevent the passage of fire and 
mice, and two courses of brick laid on horizontal bridging is also a 
good means of preventing fire or vermin ascending in a partition. 

270. Cleaning Down.—Soon after the walls are completed all 
pressed or face brick should be washed and scrubbed with muriatic 
acid and water, using either a scrubbing brush or corn broom. ‘The 
scrubbing should be continued until all stains are removed. At the 
same time all open joints under window sills and the joints in the 
stone and terra cotta work should be pointed, so that when the clean- 
ing down is completed the entire wall will be in perfect condition. 

271. Efflorescence.—After a heavy driving storm of rain or 
damp snow the face of many brick buildings will often be see to be 
covered with a sort of white efflorescence, which greatly mars the 
appearance of the brickwork. This efflorescence is due either to soda 
in the bricks, which is drawn out by capillary attraction to the sur- 
face, where it dries out, leaving a white deposit, or to pyrites in the 
clay, which when burned gives rise to sulphuric acid, which unites 
with the magnesia in the lime mortar. In either case the efflores- 
cence only appears after the bricks have been thoroughly saturated 
with moisture, either when laid or by a driving storm, perhaps several 
years after. According to Mr. Samuel Cabot it is never due to the 
bricks alone, and seldom to the lime alone. It seems to be impossi. 
ble to prevent its occurrence except by protecting the bricks by some 
waterproof or oily solution. After the white appears on the surface 
it may be washed off with clear water by vigorous scrubbing, and if, 
after the brickwork has become dry, a good coat of boiled linseed oil 
is applied, it will prevent the reappearance of the white until the life 
of the oil is destroyed, usually from three to five years, when another 
coat may be applied. Any other preparation which renders the 
bricks impervious to moisture will prevent the efflorescence. 

272. Damp-proofing*—All brick and stone walls absorb more 
or less moisture, and a wall 12 inches thick may sometimes be soaked 
through in a driving rainstorm. In the dry climates of Colorado, Ari- 
zona and New Mexico such storms rarely occur, and it is customary 





* See also page 403. 


244 BOILDING, CONSTROCTION. 


in those localities to plaster directly on the inside of the walls. In 
nearly all other portions of the country, however, it is desirable, for 
the sake of health and economy in heating, if not absolutely neces- 
sary, either to furr or strip the inside of solid walls with 1x2-inch 
strips, or to render the walls damp-proof, either by a coating of some 
kind applied to the outside of the wall, or by building the wall hol- 
low. Furring the wall with wooden strips and then lathing on them 
prevents the moisture from coming through the plastering, but it 
does not prevent the wall itself from becoming scaked, thereby neces- 
sitating more heat to warm the building and gradually tending to the 
destruction of the wall. The hollow wall is probably the best device, 
when properly built, for preventing the passage of moisture and also 
of heat, but in most cases it is also the most expensive. 

Brickwork may be rendered impervious to moisture either by paint- 
ing the outside of the walls with white lead and oil or by coating the 
wall with a preparation of paraffine, or by some of the patented 
waterproofing processes. ‘The preparations containing paraffine are 
usually applied hot, and the wall is also heated previous to the appli- 
cation by a portable heater. They give fairly good results, but are 
quite expensive, owing to the time and labor required for their appli- 
cation. 

Sylvester’s process, which consists in covering the surface of the 
wall with two washes or solutions—one composed of Castile soap and 
water and one of alum and water—has been used with much success 
for this purpose. A full description of the successful application of 
this process to the walls of the gate houses of the Croton Reservoir 
in Central Park, New York, is given in Baker’s Zvreatise on Masonry 
Construction, pp. 178-180. 

All of these preparations change somewhat the color and grain of 
the brick, and are generally considered as detracting from the appear- 
ance of the building. : 

Boiled linseed oil is often applied to brick walls, and two coats will 
prevent the absorption of moisture for from one to three years. The 
oil does not greatly change the color of the brick, and generally 
improves the appearance of a wall which has become stained or dis- 
colored in any way. 

Common white lead and oil paint is probably the best material for 
damp-proofing external walls above ground, but it entirely changes 
the appearance of the building. Painting of new work should be 
deferred until the wall has been finished at least three months, and 
three coats should be given at first, after which one coat applied 


BRICKWORK. 245 


every four or five years will answer. A preparation known as Dwuresco 
and made in England has been used in New York and Chicago fot 
damp-proofing with very satisfactory results. In Chicago it was used 
for coating the zzszde of the walls before the plastering was applied to 
prevent the moisture penetrating the plastering, which purpose it 
seems to have successfully accomplished. 

Duresco, when applied to common or soft brick, not only renders 
them weatherproof, but the color gives the permanent appearance 
for which pressed brick are valued. It dries with a hard, uniform, 
impervious surface free. from gloss, and does not flake off or change 
color. It is put up in 56-pound kegs, that quantity being sufficient 
for covering 1,000 square feet, two coats. 

Cabot’s Brick Preservative (made in Boston, Mass.).—It is claimed 
by the manufacturer that this preparation forms a thorough water- 
proofing for brickwork and sandstone, thus preventing the white 
efflorescence, the disintegration of chimneys by frost, and the growth 
of fungus. 

It does not change the natural texture of the material to which it 
is applied and leaves no gloss. It has been found by actual experi- 
ment that one coat of this preservative makes as good a waterproof- 
ing as three coats of boiled linseed oil. 

The preservative is manufactured in two forms: colorless, for use 
on any kind of brick to render them waterproof and to prevent the 
efflorescence, and,'with red color added, to bring the bricks to an 
even shade without destroying the texture. 

This material is applied with a brush in the same way as oil, no 
heat being necessary. To get the best effect the brickwork should 
first be washed down with acid (preferably nitric acid) to remove 
any efflorescence already formed. One gallon will cover about 200 
square feet on the average rough brick and a little more on pressed 
brick. One coat is generally sufficient unless the bricks are 
extremely soft and porous. 

To prevent moisture penetrating the top of brick vaults built 
underground a coating of asphalt, from $ to # of an inch thick and 
applied at,a temperature of from 360° to 518° F., seems to give the 
best results. Common coal tar pitch is often used for the purpose, 
but is not as good as asphalt. If the vault is to be covered with soil 
for vegetation the top course of brick should be laid in hot asphalt 
in addition to the coating. 

273. Crushing Strength of Brickwork.—In the majority of 
brick and stone buildings the crushing strength of brickwork need 


~ 


246 BUILDING CONSTRUCTION. 


be considered only in connection with piers, arches and under bearing 
plates or templates. The strength of brickwork varies with the 
strength of the individual bricks, the quality and composition of the 
mortar, the workmanship and bond, and also with the age of the 
brickwork. It is not the purpose here to enter minutely into the 
subject of the strength of materials, but for general practice the fol- 
lowing safe loads may be allowed for the crushing strength of brick- 
work in the cases above mentioned: For New England hard-burned 
brick, in lime mortar, 8 to 10 tons per square foot (112 to 138 pounds 
per square inch). 

Same brick laid in mortar composed of Rosendale cement 1 part, 
sand 2 parts, 12 tons per square foot (166 pounds per square inch). 


Same brick in cement and lime mortar, 1 to 3, 14 tons per square 
foot (194 pounds per square inch). 


Same brick in Portland cement and sand mortar, 1 to 2, 15 tons 
per square foot (200 pounds per square inch). 


Average hard-burned Western brick, in Louisville cement mortar, 
1 to 2, 10 tons per square foot. 


Same brick in Portland cement mortar, 1 to 2, 12$ tons per square 
foot (175 pounds per square inch). 


It should always be remembered that the strength of brick piers 
depends largely upon the thoroughness with which they are bonded, 
and the building of all piers should be carefully watched by the 
superintendent. 


274. Measurement of Brickwork.—Brickwork is generally 
measured by the one thousand bricks laid in the wall. The usual 
custom of brick masons is to take the oufszde superficial area of the 
wall (so that the corners are measured twice) and multiply by 15 for 
an 8 or g-inch wall, 224 for a 12 or 13-inch wall and 30 for a 16 or 
18-inch wall, the result being in bricks. These figures give about 
the actual number of bricks required to build the wall in the Eastern 
States, but in the Western States, where the bricks are larger, they 
give about one-third more than the actual number of bricks con- 
tained in the wall, and the price is regulated accordingly. During 
the author’s experience, in both the Eastern and Western States, he 
has never known any deviation from these figures by brick masons. 
In the West two kinds of measurement are known, &i/n count being 
used to designate the actual number of bricks purchased and used, 
and wa/l measure, the number of bricks there would be on the basis 
of 224 bricks to 1 superficial foot of 12-inch wall. 


BRICKWOKK. 247 


In regard to deducting for the openings, custom varies in different 
localities, but unless the openings are unusually large no deduction is 
generally made for common brickwork. For measuring face brick 
the superficial area of the wall is taken, with the openings omitted, 
but if the reveals of the windows are more than 4 inches they are 
added to the wall area. The number of brick to the superficial foot 
depends upon the size of the brick used, seven and one-half being 
the average number. 


Hollow walls are often measured the same as solid walls of the 
same thickness. Chimneys with 8x8 or 8x12 flues are generally 
measured as solid. 


Where stone trimmings, such as caps, sills, quoins and occasional 
belt courses are used, if the brick mason sets the stone no deduction 
is usually made for face brick, but if it is set by another contractor 
an allowance is sometimes made for the face brick displaced by the 
stone. 


As custom varies considerably in the measurement of brickwork, 
when the work is done by measurement the contract should distinctly 
state how the work is to be measured and if deductions are to be 
made for the openings and stonework. Some builders reduce all the 
brickwork to cubic feet and estimate tle cost in that way for com- 
mon brickwork. 


275. Superintendence of Brickwork.—The various portions 
of the work that require especial superintendence have been men- 
tioned in describing the manner of doing the work. In general the 
points in which brickwork is most commonly slighted are in wetting 
and laying the brick. The importance of wetting the brick is fully 
set forth in Section 238. In the laying of the brick it is often diffi- 
cult to get the mason to use sufficient mortar to thoroughly fill all 
the joints and to shove the bricks. The quality of the mortar should 
also be frequently examined, as brick masons in some localities like 
to mix a little loam with the sand to make the mortar “work well.” 


The bonding of the walls should be watched to see that the bond 
courses are used as often as specified. The bonding of piers should 
be particularly looked after. The laying of the face brick and orna- 
mental features requires more skill, but is not so apt to be slighted as 
the back of the wall. 


The superintendent should also see that the dimensions of the 
building are properly followed, openings left in their proper places, 
and the courses kept level and the wall plumb. 


248 BUOTIDING CON SLEROCGLLON. 


In very high stories, particularly in halls and churches, the 
walls should be stayed with temporary brac:s until the permanent 
timbers can be built in. It is also import-nt to see taat all bearing 
plates are well bedded, and that all floor anchors, etc., are securely 
built in; also to see that all recesses for pipes, ctc., marked on the 
plans are left in the proper places, and that all smoke and vent flues 
are smoothly plastered. 


Grarrar Vilk 
ARGHIPEEGLURATY TERRA-COTTA. 





276. Composition and Manufacture.—Terra cotta is com. 
posed of practically the same material as bricks, and its characteris- 
tics, as far as the material is concerned, are the same. Terra cotta, 
however, requires for its successful production a much better quality 
of clay than is generally used for bricks, while the process of manu- 
facture is entirely different. 

The first consideration in the manufacture of terra cotta is the 
selection of the material. No one locality gives all the clay required 
for first-class material, and each shade and tint of terra cotta requires 
the mingling of certain clays from different localities to regulate the 
color. 

A great variety of excellent clays are mined in Northern and Cen- 
tral New Jersey, large quantities being marketed annually for making 
terra cotta, as well as for fire bricks, pottery, tiles, etc. The color 
varies from light cream to a dark red. sh 

A partial vitrification of the mass is also desirable in the produc- 
tion of terra cotta, as it enhances the durability of the body. To 
achieve this, different materials are added which tend to fuse the 
body to a harder consistency. The vitrifying ingredients usually 
added to the terra cotta clays are pure white sand, old pottery and 
fire bricks finely pulverized, and clay previously burned, termed 
“ grog.” 

The clay after being mined must be properly seasoned before being 
delivered at the factory. After being received the clay is crushed 
and ground, or washed, then mixed with grit, “grog” and water. 
The clay is then piled in layers, each quality being in a separate 
layer or stratum. As many as ten or twelve strata or layers are piled 
together, and from this mass perpendicular cuts are taken, and the 
whole is again thoroughly tempered in a pug mill, or between rollers. 

After passing through the machinery, which thoroughly mixes all 
the ingredients, the plastic mass is moulded into small cakes for con- 
venience in handling and sent up to the moulding rooms. 

If several pieces of terra cotta of the same size and shape are 
required, a full size model of plaster and clay is first made, and from 


250 BUILDING CONST ROCIO. 


this a plaster mould is taken. In the making of these models and 
moulds the highest grade of skilled labor is required. When the 
moulds are dry they are sent to the pressing department ; here the 
plastic clay is pressed into the moulds by hand, and when partially 
dry the work is turned out on the floor. The ware is then ready for 
the carver or modeler, if it is decorative work that requires the use 
of their tools, or for the clay finisher if it only requires undercutting 
or some special work to make it fit in with other work. 


The work is then carefully dried on the drying floor, when it is 
ready to be put into the kilns, where it must remain seven days for 
burning and cooling before it is ready for use. The kilns commonly 
used for burning terra cotta are of the beehive, down-draft pat- 
tern. In burning terra cotta the alkaline salts contained in the clays 
yield an efflorescence, which, acting upon the silicates of the surface, 
vitrify to a greater degree the exterior of the terra coita, and this 
harder face should remain intact and under no avoidable circum- 
stances be allowed to be chipped, chiseled or broken, although the 
joints sometimes require chiseling or trimming to ensure a close fit. 


If only a single piece of terra cotta is to be made, or where no rep- 
etition is intended, no moulds are used, the clay being modeled 
directly into the required shape. ‘The finished product thus bears 
directly the impress of the modeling artist. It can be studied, 
improved or modified, and, when entirely satisfactory, burnt. On this 
account terra cotta possesses, for highly decorative work, an advan- 
tage over all other building materials. 


Terra cotta is usually made in blocks about 18 inches long, 6 to 12 
inches deep and of a height determined by the character of the work. 
To save material and prevent warping the blocks are formed of an 
outer shell, connected and braced by partitions about 1 inch thick. 
The partitions should be arranged so that the spaces shall not exceed 
6 inches, and should have numerous holes in them to form a clinch 
for the mortar and brickwork used for filling. 


277. Color.—The color of terra cotta ranges from white to a deep 
red, according to the chemical constituents of the clays used. 


Within the past ten years a great impetus has been given to the 
production of special colors in architectural cley products. In 1885 
fully four-fifths of the terra cotta produced in the United States was 
red ; now hardly one-fifth is of that color. Buffs and grays of sev- 
‘ éral shades, white and cream-white and the richer and warmer colors 
- of the fire-flashed old gold and mottled are now the prevailing colors. 


ARCHITECTURAL TERRA COTTA 251 


By the use of chemicals almost any required tone or color may be 
obtained. As a rule, however, it is safer, and a better quality of 
material is likely to be obtained, by using only those colors which are 
natural to the clay. A color which necessitates underburning or 
overburning of the clay should not be used. 

If any particular color, not natural to the material, is desired thé 
architect should consult with the manufacturer in regard to its effect 
upon the durability and quality of the finished product. 

278. Use.—The modern employments for terra cotta, architec- 
turally, are for tiles, panels and medallicns; pilasters, columns, 
capitals and bases; sills, jambs, mullions and lintels; skewbacks or 
‘springers, arches and keys; spandrels, pediments and tympanums ; 
mouldings, belt courses, friezes and cornices ; coping, chimney tops, 
cresting, finials and terminals. 

Terra cotta is also employed for brackets, consoles, gargoyles, cor- 
bels, oriel and tracery windows, and for interior use for altars, bap- 
tismal fonts, balusters, newels, pedestals, statues, niches, mantels, fire- 
place facings, and in fireproof buildings fo. base mouldings and base 
panels, and also in plain blocks for ashlar. 

Terra cotta is also suitable for all kinds of garden decorations, 
such as balustrades, ferndelabras, flower baskets and vases and other 
horticultural appliances. 

279. Durability.—The principal value of terra cotta lies in its 
durability. When made of the right material and properly burned it 
is impervious to wet, or nearly so, and hence is not subject to the dis- 
integrating action of frost, which is a powerful agent in the destruc- 
tion of stone; neither does it vegetate, as is the case with many 
stones. The ordinary acid gases contained in the atmosphere of 
cities have no effect upon it, and the dust which gathers on the 
mouldings, etc., is washed away by every rainfall. Underburned 
terra cotta does not possess these qualities in so great a degree, as it 
is more or less absorbent. Another great advantage possessed by 
terra cotta is its resistance to heat, which makes it the most desirable 
material for the trimmings and ornamental work in the walls of fire- 
proof buildings. Although terra cotta has been used in this country 
for but a comparatively short time, it has thus far proved very satis- 
factory, and the characteristics above indicated would point to its 
being, in common with the better qualities of brick, the most durable 
of all building materials. 

In Europe there are numerous examples of architectural terra 
cotta which have been exposed to the weather for three or four 


252 BUILDING CONSTRUCTI0.N. 


centuries and are still in good condition, while stonework subjected 

to the same conditions is more or less worn and decayed. 
280. Inspection.—A sharp metallic, bell-like ring and a clean, 
close fracture are good proof of homogeneousness, compactness and 
strength. Precision of the 


or ah : forms is in the highest degree 





res a = Ure - 
Cte” Te- essential, and can result only 
TORRID TALLY from homogeneous material 
and a thorough and experi- 
oy : AG enced knowledge of firing. 


No spalled, chipped, glazed. 
ES HHnenRTATaNET ES NAADNOOOQOOONOOMACO or warped pieces of terra cotta 
should be accepted, and the 
pieces should be so hard as to resist scratching 
with the point of a knife. The blocks should 
also be of uniform color, and all mouldings 
should come together perfectly at the joints. 

281. Laying Out.—lIt is impracticable, 
though not impossible, to make terra cotta in 
blocks exceeding 3 feet by 4 feet by 18 inches, 
and when the pieces exceed this size the cost is 
greatly increased. The Boston Terra Cotta 
Works have produced a column and capital of 
the Corinthian order, in white terra cotta, that 
was 14 feet 6 inches in height, the shaft being in 
one piece 12 feet-long; but such large pieces 
require great skill and care in the manufacture 
and burning to prevent warping, and are very 
cm expensive. As arule it is impracticable to span 















Lee an opening of any considerable length in one 
block, and even window sills are generally made 
in pieces about 18 inches long. Jamb blocks 

fone should not exceed 1 foot in height or there- 


abouts, Mullions, transoms and tracery should 
be made in as many pieces as the desigm will admit, and if there 
are several members in the depths of the mouldings they should be as 
much divided as possible, care being taken that each alternate course 
bonds well upon the other. The strings and cornices should be 
divided into as short lengths (18 inches to 2 feet) as convenient. 
The architect should show the jointing of the terra cotta on his 
drawings, the joints being arranged to conform with the above 


Mheow@litoonUrRAn LARKA COTTA, 253 


requirements, and the work should also be designed so as to form a 
part of the construction and to xdapt itself as far as possible to being 
divided into small pieces. When used for trimmings in connection 








iy 


<a 
SS Sea 
NL . 
Naeanaenannnannt/ Saw 





with brickwork it is very essential that the pieces shall be of the 
exact height to bond in with the courses of brick, and a small piece 
of brickwork should be built up, to get the exact heights, before the 


final drawings for terra cotta are sent to the man- 
ufacturers. All horizontal joints should be pro- 
portioned so as to be equal to about one-fourth 
the height of the joints in the adjoining face 
brickwork. For elaborate work it is generally 
necessary to consult with the manufacturers in 
regard to the best disposition of the joints. 

282. Examples of Construction.—As an 
example of the jointing of jambs and lintels, 
Fig. 170, which is from the Volta Building, 
Messrs. Peabody & Stearns, architects, is given. 

Window sills, when made of several pieces, 
should have roll joints as shown in 
Fig. 171, which should terminate 
under the wood sills rather than 
against the edge. 


Som i 


Pe ooS Goes SS he Sooo 


Cornices.—Where buildings are 
trimmed with terra cotta the cor- 

nice is generally made of the same 
material. For cornices having 
‘ considerable projection terra cotta 
possesses the advantages over stone 
of being much lighter, thus permit- 
ting of lighter walls, and in most 


ox-- 


3'> 


e@erereewpte eg & e& we ew oe 










----) 
' 


4/~ 9" 


2 


Fig. 172. 


cases much cheaper. With stone cornices it is necessary that the 
various pieces be of sufficient depth to balance on the wall. With 
terra cotta cornices, however, this is not customary, the various pieces 


254 BUILDING CONSTKOUCLTION. 


being made to build into the wall only from 8 to 12 inches and being 
supported by ironwork. When modillions are used they may gener- 
ally be made to support the construction, as shown in Figs. 172 
and 173. 

Generally small steel I or T-beams are used for supporting the pro- 
jecting members, and where the projection is so great as to overbalunce 
the weight of the masonry on the built-in end, allowing for the weight 
of snow on the projection, the inner end of the beam must be 
anchored down by rods, carried down into the wall until the weight 
of the masonry above the 
anchor is ample to counteract 
the leverage of the projection. 
Unless the wall is very heavy it 
is also advisable to anchor the 
top of the wall to the roof tim- 
bers to prevent its inclining 
outward. 

Figs. 172 and 173 * show sec- 
tions of terra cotta cornices 
that have actually been erected 
and the manner in which they 
are supported. 

Fig. 174 shows a section of 
the cornice on the Equitable 
Life Insurance Co.’s Building, 
in Denver, Col. 
These sections may be taken 

Fig. 173. ; as models of good and eco- 
nomical construction in terra 
cotta where a heavy projection is required. 

When a cornice is to be supported by ironwork the method of 
anchoring must be decided on before the work is made, as provision 
must be made in making the blocks for inserting the beams or 
anchors. Generally the beams are placed in the joints in a slot 
made for the purpose. A copy of the detail drawings should be fur- 
nished the contractor for the ironwork, to enable him to get out his 
part of the work correctly. For other examples, see Section 2874. 

283. Setting and Pointing.—Se/ting.—Terra cotta should 
always be set in either the natural (such as Rosendale or Utica) 
cements, or in Portland cement, mixed with sand, in about the same 


{ 


a 





--——ee 


2b 





* From the Clay Worker, by permission. 


AkCHIPTECT URAL TERRA COTTA. 255 


way as stone is set. As soon as set the outside of the joints should 
be raked out to a depth of # of an inch to allow for pointing and toa 
prevent chipping. ‘The terra cotta should be built up in advance of 
the backing, one course at a time, and all the voids should De Hae 


% Suurusssesse a he 


yy 


Ti. 


: ‘ 
yy 









> 
- 


a eS Rs a mony 


Ne —— 


1} 
\ 
1 
i} 
' SSSSSSSSS SOT] 
J Sey Nop 
i S N N N 
Ny KY Q 
N N a N 
\ N --No= A 
4 N 
oa | S sftex sian 7 
I 
] 
\ a Yi; 
ba) B r ac k ets Nesossomy 
x 10" fas e- Leta ATTTY 
4 
ine eet 9 on EN 
') a 
' S 
' N 
QZ 
i] V7r7774 
4 WSs 
| 
! N 
: N 
R 
’ N A 
j No 3 Y 
' D Yy 
Nee ee eee So ig Zt Yy 
inte, in 
SS -2-65- ; 


Fig. 174. 


with mortar, into which bricks should be forced to make the work as 
solid as possible. All blocks not solidly built into the walls should 
be anchored with galvanized iron clamps, the same as described for 
stonework, and, as a rule, all projecting members over 6 inches in 
height should be anchored in this way. 


256 BOUILDING CON SLIT CLION, 


Terra cotta work is generally set by the brick mason, but the spec: 
ifications should distinctly state who is to do the setting and pointing. 


Pointing.—After the walls are up the joints should be pointed with 
Portland cement colored with a mineral pigment to correspond with 
the color of the terra cotta. The pointing is done in the same way 
as described for stone, except that the horizontal joints in all sills, 
and washes of belt courses and cornices, unless covered with a roll. 
should be raked out about 2 inches deep and caulked with oakum 
for about 1 inch and then filled with an elastic cement 


284. Time.—One of the principal objections to the use of terra 
cotta is the time required to obtain it, especially when the building is 
some distance from the manufactory. Some six weeks are required 
for the production of terra cotta of the ordinary kind, and the archi- 
tect should see that all the drawings for the terra cotta work are 
completed and delivered to the maker at as early a stage in the work 
as possible, so that he may have ample time to produce it. 


Small pieces of terra cotta may sometimes be obtained within two 
weeks from the receipt of the order when the moulds are already on 
hand. It is always more expensive, however, to attempt to turn out 
work in such short order, and inexpedient on account of the risks in 
forcing the drying. 

285. Cost.—A single piece of terra cotta, or plain caps and sills, 
costs about the same as freestone, when the rough stone can be 
delivered at a price not exceeding ninety cents per cubic foot. When 
a number of pieces exactly alike are required, however, it can be 
produced in terra cotta cheaper than in stone, unless the terra cotta 
has to be transported at a large cost for freight. The advantage in 
point of cost in favor of terra cotta is greatly increased if there is a 
large proportion of moulded work, and especially if the mouldings 
are enriched, or if there are a number of ornamental panels, carved 
capitals, etc. It should always be remembered that if economy is 
desired it can best be obtained by a repetition of the ornamental fea- 
tures, so as to require as few different models as possible. When 
stock patterns can be used the cost is also considerably less than when 
the work has to be made from special designs. 


The use of terra cotta for trimmings, and especially for heavy cor- 
nices, in place of stone, often reduces the cost of the walls and foun- 
dations, as the weight of the terra cotta will be much less than that 
of stone, and the walls and foundations may be made lighter in con: 
sequence. | 


ARCHITECTURAL TERRA COTTA. 257° 


286. Weight and Strength.—The weight of terra cotta in 
solid blocks averages 122 pounds per cubic foot. When made in hol- 
low blocks 14 inches thick the weight varies from 65 to 85 pounds 
per cubic foot, the smaller pieces weighing the most. For pieces 
12x18 inches or larger on the face, 70 pounds per cubic foot should 
be a fair average. 

The crushing strength of terra cotta blocks in 2-inch cubes varies 
from 5,000 to 7,000 pounds per square inch. 

Hollow blocks of terra cotta, unfilled, have sustained 186 tons per 
square foot on blocks 1 foot high. 

From these and other tests the author would place the safe work- 
ing strength of terra cotta blocks in the wall at 5 tons per square foot 
when wxzjilled and 10 tons per square foot when filled solia with brick- 
work or concrete. 

If it is desired to test the strength of special pieces, two or three 
small pieces should be broken from the blocks and ground to 1-inch 
cubes, and then tested in a machine. Should the average results fall 
much below 6,o00 pounds the material should be rejected. 

Transverse Strength of Modillions—A cornice modillion measur- 
ing 114 inches high and 8 inches wide at the wall line, with a projec- 
tion of 2 feet, carried a load of 4,083 pounds without injury. A 
similar modillion 54 inches high, 6 inches wide, with a projection of 
14 Inches, broke under 2,650 pounds. Another bracket from the 
same mould, inserted in the same hole, sustained 2,400 pounds with- 
out breaking. 

287. Protection.—The carpenter’s specifications should provide 
for boxing all moulded and ornamental work with rough pine boards 
to guard against damage during construction. Hemlock is unsuited 
for this purpose, as it is liable to stain the terra cotta. 

2871. Other Examples of Terra Cotta Construction.— 
Many excellent illustrations of terra cotta construction have been 
contributed to the Brickbuilder during the past two years (1897-98), 
by Mr. Thomas Cusack, which are accompanied by a great amount 
of practical information and advice regarding the subjects treated. 

Through the courtesy of Mr. Cusack and the publishers, we are 
enabled to reprint two illustrations, Figs. 174@ and 4, showing the 
best construction of a balcony and of parapet balustrading. 

Fig. 174@ illustrates the design of a conventional balcony, such as 
might be projected from a second or third story window by way of 
embellishment. The manner in which it was constructed is shown 
by the section below the elevation. The objections to this construc- 


2572 BUILDING CONSTRUCTION. 


tion, briefly stated, are: 1. “ The cantilevers have a strength out ot 
all proportion to the load that could by any possibility be put upon 
them.” 2. ‘They are placed about 7 inches too high, cutting 
through the top bed of the modillions and into the bottom of the 
platform, thereby causing an incurable weakness in both.” 3. “The 





















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Te deges 
=F | Esae 
= U 
=[eo ROS AE ost 
a8 hes [Eee ae —— nZaQ 
1 |. a 28 
f_ a y | 






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Lhe 


Lid 


GE 












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) TL. 
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Fig. 174a. 










MKT 
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oe ep 
4 SW me 
= ea ear P SS | 





















KAS (Se 


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“ld 


















inverted tee resting upon them is not only quite unnecessary, but 
positively suicidal, so far as the terra cotta is concerned.” <A plan, 
such as is shown in sections 44, BB, and CC, would have been much 
simpler, less expensive and avcided the objections above ~1oted. 


AKCHITELCLTORAL TERRA COTTA, 












































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2576 | BUILDING CONSTRUCTION. 


“The modillion in this case would be made with four walls and 
one horizontal partition, forming two open chambers asat CC. Into 
the upper one of these we would insert a 3$ by 5-inch I-beam, the 
end of which would be attached to floor beam, and the surrounding 
space filled with concrete, as at BB. Inthis way we would get the 
full strength of the cantilever cased in cement, without weakening 
the modillions by needlessly cutting through its outer shell. The 
platform would be made in three complete blocks of moderate size, 
two of them resting directly on the brackets, the centre block joggle- 
jointed on two sides with a third side built into the wall.” 

A balcony constructed in this way would have a strength many 
times in excess of any weight ever likely to be placed upon it. 

Fig. 1740 shows the construction of the terra cotta cornice and 
parapet of a residence at Madison Avenue and Thirty-ninth Street, 
New York, which may be taken as the typical construction of such 
work. 

The balusters are made in three pieces, for the reasons that balus- 
sters made in one piece are subject to cleaving where the halves are 
united, and are very liable to twist in the kiln, besides being more 
expensive in the first instance with no compensating advantages. If 
the cornice were much broken by piers or angles, the diagonal 
stays to roof might be omitted. 





CuapTeER IX. 


FIREPROOFING 


288. Most of the materials employed for protecting the structural 
portions of buildings from fire and heat, and for filling between the 
floor beams and rafters, are of earthy composition and come within 
the province of the mason or plasterer. 

The constructive fireproof materials—z. ¢., those which have to 
support any weight—most extensively used in this country are: 
dense, hollow tiles, porous terra coita tiles or blocks and various con- 
crete compositions, generally combined with steel in the shape of 
small bars, wires or netting. ‘These materials are used in different 
shapes and in different ways, both of which are, as a rule, covered 
by patents controlled by large manufacturing corporations. Most of 
these manufacturing corporations also take contracts to furnish all 
the fireproofing material required in the building and to put it in 
place, leaving the building ready for the plasterer and carpenter. A 
few manufacturers, however, prefer to confine their business to man- 
ufacturing the material, and of late years the practice has become 
quite general, especially in the East, for the owner or general con- 
tractor to buy tiles and the mason contractor on the job to build 
them in place in the building. 

While with contractors of large experience this practice has worked 
very well, it will generally be found more satisfactory to the archi- 
tect to have the party that furnishes the material put it in place, as 
the responsibility for the proper and prompt execution of the work is 
then undivided. If the putting in place of the fireproofing must be 
done by another party, the contract should be let to some one who is 
familiar with that kind of work and with the material to be 
employed. 

Whichever way the contract is to be let, however, it is well for the 
architect to specify both the kind and quality of the material to be 
employed and also the way in which the work is to be done. It is 
also advisable and customary to require that the floor construction 
shall be subjected to certain tests before it is accepted. 


FTREPROOFING. 259 


The kind of material and method of fireproofing that is to be 
employed should also be decided upon before the framing plans are 
made, as some systems require different framing than others. Some 
systems also effect a sufficient saving in dead weight to enable lighter 
beams and columns to be used than are required where heavy arches 
of dense tile are used. 


If competitive bids are desired to assist in determining the kind of 
fireproofing to be employed, these can usually be obtained before 
the plans are completec, the position of the columns determining the 
spans and width of archies. . 


If it is decided to use either porous or dense tile arches it is not 
absolutely necessary to specify any particular make of tile, but the 
specifications may be written so that any tile may be used which ful- 
fills the conditions therein contained. 


The subject of fireproof construction has received a great deal of 
attention during the past few years, and the increased demand for a 
safe and economical system of fireproofing has led to the introduction 
of many systems, nearly all of which, however, may be said to be still 
in the experimental state. A great many tests have been made of 
the strength of fireproof floors, but many of these have been con- 
ducted in such a way as to be of little value in determining the real 
strength of the system. As it is not the purpose of this book to enter 
extensively into the subject of strength of materials, but rather to 
describe methods of construction, we shall here undertake only to 
describe the methods of fireproofing most commonly in vogue in this 
country, referring the reader to the author’s ‘ Pocket Book,” and 
especially to a record of tests on fireproof floors published in the 
Brickbuilder for 1895, for more complete data relating to their 
strength and to the designing of the metal work. 

For lack of space it will also be necessary to confine ourself to the 
description of the fireproofing of buildings constructed of incombus- 
tible materials. The fireproofing of buildings constructed with 
wooden joist and posts is now almost entirely confined to plastering 
applied to some form of metal lathing, or to plaster boards or blocks 
These will be described in Chapter XI. 

The fireproofing of non-combustible buildings may be divided into 
three divisions—floor construction, partitions and the casings of 
posts, girders, trusses, etc. For convenience we will describe the dif- 
ferent methods under the above headings. first, however, describing 
briefly the different materials employed ir fireproofing. 


26o BUILDING CONSTRUCTICN. 


FIREPROOFING MATERIALS. 


289. Various materials have been introduced at different times for 
the purpose of making buildings fireproof. Experience has shown, 
however, that the only practical method of producing a really fire- 
proof building is by using only incombustible materials for its struc. 
tural parts and protecting all structural metal work with some fire, 
water and heat-resisting material. The ideal fireproof building would 
undoubtedly be one that was constructed entirely of brickwork and 
serra cotta, with brick, cencrete or tile floors or roofs, built in the 
form of vaults sprung from brick piers and without the employment 
of structural metal work. Such a building, if properly designed and 
built, would withstand the combined action of all the elements for 
centuries. Modern commercial requirements, however, demand that 
the vertical supports shall be as small and as far apart as possible, 
and that the floors shall be thin and have level ceilings, and these 
can only be obtained by the use of metal work. 


The materials that have been found to successfully answer the pur- 
poses of modern fireproofing are confined to the products of clay, 
some concretes and lime and cement mortars under certain con- 
ditions. 


290. Clay Products.—Of all fire-resisting materials burnt clay: 
has the most numerous applications in incombustible building. For 
the construction of floors and partitions, and for the casing of posts 
and girders, the clay is moulded into hollow tiles or blocks of two 
general kinds. 

These are known by several different names: The one by such as 
porous terra cotta, terra cotta lumber, cellular pottery, porous tiling, 
soft tiling, etc.; the other by fire clay tile, hollow pottery, hard tile, 
terra cotta, dense tiling, etc.* For convenience the first will be here- 
inafter referred to as porous tiling and the second as dense tiling. 
The terms “hollow tiling” and “fireproof tiling ”’ will be used when 
both are referred to in a general way. 

291. Porous tiling is formed by mixing sawdust and finely cut 
straw with pure clay and submitting it to an intense heat, by the 
action of which the sawdust is destroyed, leaving the material light 
and porous like pumice stone. When properly made it will not crack 
or break from unequal heating or from being suddenly cooled by 

* The Pioneer Fireproof Construction Company have also recently introduced a new material 
which they call ‘‘semi-porous hollow tile.’’ This material is considerably. lighter than the 


dense tiles formerly made by them, and is claimed to stand the fire and water tests equally as 
well as porous tiling. 


FIREPROOFING. 261 


water when in a heated condition. It can also be cut with a saw or 
edge tools, and nails or screws may be easily driven into it for secur- 
ing interior finish, slates, tiles, etc. 


For the successful resistance of heat, and as a non-conductor, the 
author believes there is no building material equal to it, especially 
when used in thin sections. To obtain the above qualities in their 
fullest extent the blocks should be manufactured from tough plastic 
clays, with which a small percentage of fire clay should be mixed. 

Porous tiles, when properly made and burned, shouid be compact, 
tough and hard, ringing when struck with metal. Poorly mixed 
pressed or burned tiles, or tiles from short or sandy clays, present a 
ragged, soft and crumbly appearance, and are not desirable. 

Porous tiles for floor construction, or wherever they may have to 
carry considerable weight, should be made with not Jess than 1-inch 
shells, and the webs or partitions dividing the spaces should be from 
# to finch thick, according to the size of the hollows. 

Porous tiling possesses the advantages over hard tiling of being 
light, tough and elastic, while dense tiles are hard and brittle. 

292. Dense tiling is made generally of fire clay, combined with pot- 
ters’ clay, plastic clays or tough brick clays, moulded by dies into the 
various hollow forms required for commercial use. The clay is sub- 
jected during its manufacture to a high pressure while in a moist or 
damp state, which gives the finished material great crushing strength. 
After drying the tiles are burned lke terra cotta in a kiln. 

Previous to the year 1890 dense tiling was almost exclusively used 
for the construction of floor arches, and even at the present day it 
appears to be more extensively used for this purpose than the porous 
tiling, the latter being confined principally to the end-method system 
of floor arches. 

Dense tiling in solid blocks is unquestionably stronger than porous 
tiling, although more brittle. When made from fire clay it is undoubt- 
edly a thoroughly fireproof and non-conducting material, but it will 
not stand the combined effects of fire and cold water as well as the 
porous tiling. In outer walls, exposed to the weather and required 
to be light, dense tiling is very desirable. Some manufacturers fur- 
nish it with a semi glazed surface for outer walls of buildings. For 
such use it has great durability and effectually stops moisture. 

In using dense tiling for fireproof filling care should be taken that 
the tiles are free from cracks and sound and hard burnt. 

293. Concretes.—Concrete made of Portland cement, mixed 
with sand, crushed stone, pieces of burnt fire clay, broken bricks or 


262 BOLLDING. CON SEROCLLON, 


tiles, has been successfully used in Europe as a fireproof material 
for many years, and what few tests have been made upon it appear 
to prove that it is a highly fire-resisting material, and it is now so 
considered by well-informed engineers and architects. 

Professor Bauschinger, of the Munich Technical School, tested 
pillars of various materials by repeatedly heating them red hot and 
then drenching them with water. In his report he says: “Of all 
materials tested Portland cement concrete stood the best, and ordi- 
nary and clinker brick laid in Portland cement mortar stood almost 
equally as well.” 

Concrete construction has been largely used in California for 
many years on account of its fireproof qualities, and it is probable 
that it will be much more extensively used in the future in all por- 
tions of the country. 

Plaster Concretes—In Paris a composition of plaster of Paris and 
broken brick, chips, etc., has been used for generations for forming 
ceilings between beams, and its durability is there unquestioned. A 
composition consisting of 5 parts by weight of plaster of Paris and 1 
part of wood shavings, mixed with sufficient water to bring the mass 
to the consistency of a thin paste, has been lately introduced in this 
country in connection with the Metropolitan system of floor con- 
struction. It is claimed that this material 1s so remarkable a non- 
conductor of heat that a moderate thickness of it prevents the pass- 
age of nearly all warmth. 

“In severe fire tests the beams have remained cold, and con- 
sequently were unaffected. When exposed to flame for a long 
time the composition is attacked to a depth of from ,';'to $ of an 
inch, the remainder being unaffected, and when water is thrown upon 
it the mass does not fly or crack. When made thoroughly wet the 
composition is not destroyed.” 

This composition is much lighter in weight than ordinary cement 
concrete. 

Lime mortar, and most, if not all, of the hard mortars or patent 
plasters, when applied on metal lathing, will resist almost any degree 
of heat, and will withstand the action of water for a long time. 


FLOOR CONSTRUCTIONS. 


294. The improvements in fireproof floor construction during the 
past fifteen years have been many and in rapid succession. Previous 
to 1880 so-called fireproof floors were constructed of brick arches 
turned between the lower flanges of wrought iron I-beams. These 


FIREPROOFING. 263 


arches, with the concrete used for leveling, were very heavy, and as 
the bottoms of the beams were unprotected and the ceiling formed by 
the arches was very undesirable, brick arches soon gave place to 
arches of hollow dense tile. The increased demand for fireproof 
construction, taken in conjunction with the reduction in the prices 
of steel and fireproofing which occurred about the year 1889, led to 
many improvements in the designs for hollow tile floor arches, and 
also to the introduction of various systems of construction based 
upon the use of concrete and plaster compositions, combined with 
steel wires, bars and cables, used in different shapes and in different 
ways, the chief aim of the inventors or designers being to secure the 
lightest and most economical floor consistent with ample strength 
and thorough fire protection. 


In the following pages the author has endeavored to give an 
impartial description of the various systems at present approved by 
the leading architects and engineers. : 


295. Hollow Tile Floors.—fvlat Construction.—There are 
three general schemes of flat.tile construction at present in vogue in 
this country. The. first and oldest is known as the sede method, in 
which the tiles lie side by side between the beams, as shown in Figs. 
175,176 and 177. Inthe second scheme, known as the exd method, 
the blocks run at right angles to the beams, abutting end to end, as 
shown in Figs. 178 and 180. The third method is a cross between 
the first and second, the skewback (or abutment) being made as in 
the side construction, and the “interiors” or keys abutting end to 
end between the keys, as shown in Fig. 181. This method is known 
by different names, such as the “ Johnson Arch,” ‘‘ Excelsior Arch,” 
“Combination Arch,” etc. 


296. Side-Method Arches.—The hollow tile floor arches first 
used in this country were made of dense tile, formed essentially like 
those shown in Fig. 175, except that no provision was made for pro- 
tecting the bottom of the beams except by the plaster on the ceiling. 
It was soon found that the bottom of the beams must be more thor- 

- oughly protected from heat, as when unprotected they warped and 
- twisted so badly during a fire as to destroy the building. The skew- 
backs were, therefore, made so as to drop from # to 1 inch below the 
bottom of the beams, and either to extend under the beam or else to 
hold a thin tile dovetailed between them, as shown in the figure. 
Arches of this type were used for several years, but it was 
found that they were not strong enough to sustain severe loads 


264 BOLILDING CONST AO CL Oli 


and the sudden strains caused by moving heavy safes, or to withstand 
the rough treatment and heavy weights that floors are subjected to 
while the building is in course of erection. The blocks were, 
therefore, strengthened by the introduction of horizontal and vertical 
webs, resulting in the shapes shown in Figs. 176 and 177, which rep- 
resent the best types of dense tile arches with ribs parallel to beams 
made at the present time. 


Arches similar to these are also made of porous tiling, but this 
































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material is more generally used in the end-method types. Most of 
the side-method arches have beveled joints, which are parallel to the 
sides of the key, as shown in Fig. 176, although arches are now made 
with radius joints, as shown in Fig. 177. Theoretically the latter 
joint should make the strongest arch, but the increased cost of mak- 
ing so many different shapes of blocks prevents it being much used. 

The blocks in the side-method arches break joint endways, so as 
to completely bond the arch, as shown in Fig. 176. Arches of the 
type shown in Figs. 176 and 177 undoubtedly have ample strength 
for all ordinary purposes, and the author believes there is no record 


FIREPROOFING. 265 


of their failure when in actual use in buildings. The few compara- 
tive tests that have been made, however, would appear to prove that 
for a given weight the side-method arch is not as strong as those 
built on the end method. 

297, End-Method Arches.—In this method the blocks are 
generally made rectangular in shape, with one vertical and one hori- 
zontal partition, and with bevel end joints. In this system it is not 
the practice to have the blocks in one row break joint with those in 
another, as it entails extra expense in setting. When this is done, 
however, the substantialness of the floor is increased. 





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Fig. 180. 


The most common type of end-method arch is that shown in 
Fig. 178, which was first brought into general use by Mr. Thomas 
A. Lee, and is often designated as the “ Lee End-method Arch.” It 
has the advantage of simplicity and economy in manufacture, as all 
the blocks for a given depth of arch can be made with one die. 
Most, if not all, manufacturers making this type of arch use porous 
terra cotta in its construction. These arches require very heavy 
webs in order to give sufficient bearing on the beams, which greatly 
increases the weight of the arch. Fig. 179 shows an isometric view 
of one of the “butment”’ pieces or hanches. 


266 BUILDING CONSTRUCTION: 


Some complaint has been made by architects that they find it dif- 
ficult to get a strictly flat ceiling with this type of arch. 

The open ends of the hollow tiles not being well adapted to receive 
mortar for the mortar joint, the mortar often squeezes out, permitting 
some of the blocks to drop below the others. 

As there is no bond between the rows of tiles, if a single tile in 
a row should be broken or knocked out of place, the entire row will 
fall, and for the same reason a single tile cannot be omitted for mak- 
ing a temporary hole, as may be done in side-method arches. 

Where the tile blocks abut endways they-should be cut to fit per- 
fectly between the beams, so that the divisions will abut perfectly 
against each other. Solid plates may, however, be placed between 
the ends of the tile blocks without injurious effect, and, in fact, the 
author believes that such plates would give a stronger joint. 































































































































































































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Fig. 18. 


Fig. 180 represents the transverse system of floor arch construction 
now made by the Pioneer Company. ‘The interiors are of the same 
shape as those used in their former system (Fig. 181), sometimes 
called the Johnson Arch, but instead of using parallel abutments end- 
section abutments are used, as shown in the figure. Whenever the 
former system was tested to destruction the abutments were almost 
invariably the parts which failed. It was for this reason that a dif- 
ferent style of abutment or skewback was adopted, and the manu- 
facturers claim that they now have the strongest and lightest flat 
tile arch on the market. This arch is made of dense tile, with webs 
and flanges $ and # inches thick respectively. 

298. Combination of Side and End Methods.—There are 
several styles of combination arches now manufactured. The object 


in making this shape of arch is to obtain the strength of the end- 





al Bey 


FIREPROOFING. 267 


method construction and at the same time get a flat bearing for the 
skewbacks. In order, however, to develop the full strength of the 
interior blocks the skewbacks should be made very strong and with 
several partitions, as they are generally the weakest portion of the 
arch. 

Fig. 181 illustrates the “Excelsior” dense tile arch made by 
Henry Maurer & Son. This arch was patented by Mr. E. V. John- 
son, iormerly general manager of the Pioneer Company, and was for- 
merly made also by that company. The shape of the interior blocks 
undoubtedly gives great strength with the minimum amount of 
inaterial. 

This arch has been quite extensively used in Chicago and also in 
Eastern cities, and apparently has given general satisfaction. 

An end-method, dense tile flat arch, with side-method skewbacks, 
is also made by the Empire Fireproofing Company. ‘The interior 

















Fig. 182. 


blocks have vertical and horizontal partitions similar to the Lee tile, 
but the sides of the tile, instead of being a true plane, have an offset 
at the middle of the tile, so that one course laps over the other, 
thereby preventing any possibility of the tiles slipping down, which 
sometimes occurs 1n the ordinary end-method arch. 

Fig. 182 shows a triple web combination flat arch made by the 
Hocking Clay Manufacturing Company and also their patent flange 
cover for beams. . 

299. Depth, Weight and Strength of Flat Tile Arches.— 
Flat arches made on the side-method principle may be had in depths 
from 6 to 12 inches, and those made on the end method from 6 to 15 
inches. 

The depth of arch most frequently used for Oiice buildings and 
retail stores is 10 inches, the girders being spaced so as to use 10-inch 
steel floor beams spaced from 5 to 6 feet apart. Asa rule the depth 
of the arch should be about equal to the depth of the beam, as it is 
just about as cheap and much better construction to use deeper til- 
ing and less concrete filling. 7 


268 BUILDING CONSA£LOCTION, 


The following tables give the published weights and safe span for 
both dense and porous tiling : 


TABLE X.—WEIGHTS AND SPANS FOR FLAT HOLLOW TILE ARCHES. 














DENSE TILE. 





Depth of Arch. Span between Beams. Weight per sq. ft. 
6 inches. 3 feet 6 inches to 4 feet. 22—29 pounds. 
7 inches. 4 feet to 4 feet 6 inches. 27—32 pounds. 
8 inches. 4 feet 6 inches to 5 feet 6 inches. 30—35 pounds. 
g inches. 5 feet to 5 feet g inches. 32—37 pounds. 
Io inches. 5 feet 9 inches to 6 feet 6 inches. 34—4I1 pounds. 
12 inches. 6 feet 6 inches to 7 feet 6 inches. 37—38 pounds. 





POROUS TILE—END METHOD. 








6 inches. 3 feet to 5 feet. 21 pounds, 
7 inches. 3 feet 6 inches to 5 feet 6 inches. 24 pounds. 
8 inches. 4 feet to 6 feet. 27 pounds. 
g inches. 4 feet 6 inches to 6 feet 6 inches. 30 pounds. 
Io inches. § feetto 7 feet, 33 pounds. 
12 inches. 6 feet to 8 feet. 37 pounds. 
15 inches. 7 feet 6 inches to Io feet. 43 pounds. 








The weight of the Pioneer Company’s transverse arches (Fig. 180), 
as given by the manufacturers, is as follows: 


DEPTH OF ARCH. |WEIGHT PER SQ. FT.|| DEPTH OF ARCH. |WEIGHT PER SQ. FT. 


8 inches. 22 pounds. 12 inches. 30 pounds. 
g inches. 24 pounds. 15 inches. 35 pounds. 
10 inches. 26 pounds. D7 inches. 40 pounds. 








The lighter weights in the third column for dense arches are for 
the “Excelsior” arch; the heavier weights are for the arches shown 
in Figs. 176 and 177. 

From a few tests of the weight of blocks, as they were being deliv- 
ered at the building, the author is inclined to believe that the actual 
weights of both dense and hollow tile will generally run at least 10 
per cent. over those given in manufacturers’ catalogues. (See Sec- 
tion 312.) ? 

The strength of hollow tile floors can only be determined by actual 
experiment. 

At the tests made at Denver,* December, 1890, two 1o-inch dense 
tile arches (5-foot span), with one horizontal web and built on the 
side method, failed under distributed loads of 271 and 428 pounds per 





*See full account in American Architect and Building News, March 28, 1891. 


FIREPROOFING. ar OG 


square foot, respectively. A porous tile end-method arch, 1o inches 
deep, with two horizontal webs, sustained 757 pounds per square 
foot for two hours without breaking. 

Tests made at Richmond, Va., in 1891 of 6-inch and 12-inch side- 
method arches made by the Empire Fireproofing Company, showed 
a variation of from 288 to 579 pounds per square foot for the 6-inch 
arches and from 554 to 1,057 pounds per square foot ror the 12-inch 
arches, the average strength of the nine 12-inch arches being 858 
pounds per square foot. 

The Pioneer Company describe a test of a 15-inch flat arch similar 
to that shown in Fig. 181, in which the arch sustained 3,287 pounds 
per square foot (over an area 4x4 feet) before‘ breaking. 

The average breaking weight of five arches of 10-inch tile, with 
spans varying from 4 feet 11 inches to 5 feet 6 inches, tested by the 
Metropolitan Company, was 519 pounds per square foot. 

It is generally considered by engineers that a tile arch should not 
fail under a load less than five times that which it is intended to 
carry. Arches of the types shown in Figs. 176-182, inclusive, if 
properly set and built of sound blocks, should be abundantly safe for 
office floors and light stores when proportioned according to the 
table. The instances where tile arches have failed when in actual 
ise are very few indeed. 

The cost of hollow tile arches of either kind, set in place ready for 
plastering in lots of 20,000 square feet, ranges from 14 cents to 25 
cents per square foot, according to size and weight of the tile. In. 
Chicago the average price Is 20 cents. 

300. Manner of Setting Tile Arches.—Hollow tile arches 
of whatever type should be set in a good Rosendale or Portland 
cement mortar on plank centring, slightly cambered. ‘The best cen- 
tring for flat arches is that in which the planks run at right angles 
to the beams and rest on 2x6 sound lumber centre pieces, placed mid- 
way between the beams and extending parallel with them. These 
centre pieces are supported by T-bolts from like centre pieces above, 
crossing the beams. The planks on which the tiles are laid should 
be 2-inch plank, dressed on one side to a uniform thickness and laid 
close together. If the soffit tile is a separate piece it should first be 
laid directly under the beam on the planking; if a projecting skew- 
back is used, then the skewbacks must first be set, after which the 
centring is tightened by screwing down the nuts on the T-bolts until 
the soffit tile, or skewbacks, are hard against the beams and the 
planking has a crown not exceeding } of an inch in spans of 6 feet. 


270 BUILDING CONSLARUCTION. 


This system gives what is very essential—a firm and steady centre on 
which to construct the flat tile work. The tiles should be shoved in 
place with close joints and keys should fit close. The centres should 
remain from twelve to thirty-six hours, according to condition of 
weather, depth of tiling and mortar used. When centres are 
“struck” the ceiling should be straight, even, free from open joints, 
crevices and cracks, ready to receive plastering. 


Wherever openings are required through the floor they may be 
made by punching a hole through the blocks ; or, if the side-method 
arch is used, a single block may be omitted. Small holes may after- 
ward be plugged up with mortar and broken pieces of tile. 


The variations in width of spans between beams is provided for by 
supplying tiles of different sizes, both for interiors and keys, whereby 
a variety of combinations can be secured. A great variety of skew- 
backs are also provided for fitting different sizes of beams. 


Tie-Rods.—All forms of flat or segmental tile arches require that 
the beams supporting them shall be bolted together with tie-rods to 
take up the thrust of the arch. These tie-rods are usually ? inch in 
diameter and spaced from 5 to 7 feet apart. They should be secured 
to the web of the beam near the bottom flanges and drawn tightly in 
place by nut and thread. = 


301. Protection.—The laying of flat construction in winter 
weather without roof protection should not be practiced in climates 
where frequent severe rain and snow storms are followed by hard 
freezing and thawing, as the mortar joints are liable to be weakened 
or ruptured, resulting in more or less deflection of the arches. When 
it is intended to plaster on the under side of the arches ‘the architect 
should see that the smoke and soot from the boiler used for the hoist- 
ing plant are not allowed to strike the arches, as neither can be 
removed, and they are sure to stain the plaster. For the same 
reason the architect should see that only clean water is used for mix- 
ing the mortar, and that it is not allowed to flow over the arches, 


Many architects have had trouble, where flat tile arches have ‘been 
used, from stains and excrescence appearing on the plastered ceiling 
after the latter had become dry. Such stains cannot always be con- 
cealed, even by oil paint, and the only way in which they may be 
avoided is by observing the above precautions and‘ not plastering 
until the arches are well dried out. A coating of Duresco applied to 
the ‘bottom of the arches before plastering has been recommended as 
a safe precaution against stains. © ; 


FIREPROOFING. 271 


The architect should also see that the green arches are not over- 
- loaded with building material by the other contractors. 

302. Floor and Ceiling Finish.—The under side of flat tile 
arches is usually finished with two coats of plaster applied directly to 
the bottom of the tiles. If there are inequalities in the surfaces of 
the arches they should be filled with natural cement and sand mor- 
tar before plastering. False plaster beams may either be formed on 
metal furring, bolted to the under side of the arches and covered with 
. wire lathing, or the furring may be of wood, as its consumption in 
case of fire would in no way endanger the building. Metal furring, 
however, is better, as it does not shrink. 

Wooden furring strips to form nailings for wood mouldings, etc., 
may be secured to the soffits of the arches by punching slot holes in 
the bottom of the blocks and inserting T-headed bolts. 

The upper surface of the arches is generally covered with concrete 
of a sufficient depth to allow for bedding in it the wooden strips to 
which the floor boards are nailed. 

The general custom in regard to the size of floor strips and depth 
of filling is to use 2x4-inch well-seasoned wood strips, beveled to 2 
inches wide on top and laid at right angles to the beams and 16 
inches apart from centres. The concrete is first leveled to the tops 
of the highest beams and the strips then laid in place by the carpen- 
ter. The mason then fills between the strips to within } inch of 
their top with concrete, pressed down hard against the strips. A 
single matched flooring is chen nailed to the wood strips. In New 
York 3x4-inch strips are often used, the strips being notched down 
over the beams 1 inch. The strips, also, do not always run at right 
angles to the beams, although the general opinion appears to be that 
they should do so wherever practicable. 

The general custom amongst Chicago architects is to allow 34 
inches from the top of the beams to the top of the finished floor. 
This gives a sufficient space between the beams and flooring for run- 
ning gas pipes or water pipes, as shown in Fig. 183. Wherever build- 
ings are piped for gas, and especially office buildings, it is absolutely 
necessary to leave sufficient space between the tops of the steel beams 
and the bottom of the flooring for running branches to centre outlets. 

Wherever the nailing strips cross the floor beams or girders they 
should be fastened to them by means of iron clamps, made so that 
one end can be hooked over the flange of the steel beam and the 
other end driven into the side of the wood strip. When the strips 
run parallel with the beams it is good practice to nail pieces 


ey BUILDING CONSTRUCTION. 


of hoop iron across the under side of the strips about 4 feet apart, 
to hold the strips more firmly in place, as the concrete alone does 
not hold them with sufficient firmness. The hoop iron strips should 
be 14x+ inch and 1o inches long, and should be secured by two 
clout nails. 

The concrete used for the filling on top of the arches and between 
the nailing strips should be made of screened boiler cinders, mixed 
with lime mortar gauged with plaster of Paris or Portland cement, 
the cinders being used on account of their lightness. The concrete 
must become thoroughly dry before the flooring is laid. As this 
requires considerable time, dry cinders without any lime or cement 
has been used in a few office buildings where it was necessary to rush 
their completion. The best architects, however do not recommend 
the use of dry cinders when it can be avoided. 

Occasionally, where the beams are of unusually long span, a ro-inch 
or 12-inch arch is set between 15 or 20-inch beams. In such cases 
it is better to fill in on top of the ‘arches with partition iilésor 
N-shaped tile made for the purpose. 

If the floors are to be tiled the concrete between the bottom of the 
tiles and the top of the arch should be made of Portland cement, 
sand and crushed stone. 

Wooden floors should be laid continuously over the entire area to 
be covered, without reference to partitions, where the same are liable 
to be changed to suit tenants. Permanent partitions should be 
erected before the floors are laid. 

Fig. 183 shows the floor construction used in the “ Fair” Build- 
ing, Chicago, Jenney & Mundie, architects, and also the fireproofing 
of the columns. This cut is also typical of many other buildings 
recently erected in Chicago. 

303. Segmental Tile Arches.—Where a flat ceiling is not 
essential, and for warehouses, factories, breweries, etc., the segmental 
arch gives the strongest, best and cheapest (considering the saving in 
ironwork) fireproof floor that can be built of tile. Segmental arches 
can be used for spans up to 20 feet, thus dispensing entirely with the 
usual floor beams ; they also effect a considerable saving in the dead 
weight of the floor, thereby enabling the columns and girders to be 
made lighter. 

There are at present two distinct systems of segmental anchess in 
vogue in this country. 

FHfollow Tile Segmental Arches.—The most common form of seg- 
mental arch is that shown in Fig. 184, which is made of hollow 


FIREPROOFING. 273 


blocks, usually 4, 5, 6 or 8 inches square and 12 inches long, the tile 
being laid so as to break joint longitudinally of the arch. Nearly all 
manufacturers of hollow tiling make one or more shapes for seg- 
mental arches, and also different styles of skewbacks to use with them. 
Hollow tiles for segmental arches are also made both of dense and 
porous tiling. The latter is generally considered as the best material 
for this purpose. Segmental arches should have a rise of not less 
than 1 inch per foot of span, and 14 inches wherever practicable. 





SCALE OF FEET AND INCHES. 


ISOMETRIC VIEW 


Fig. 183. 


With this*type of arch it is better to use a very heavy or solid 
skewback without the flange projection, as the thrust on the skew- 
back is very great where the arch is of wide span. The bottom flange 
of the beam should be covered with heavy, stiffened wire lath before 
the skewbacks are set. When plastered the ceiling has the appear- 
ance shown in Fig. 184. 

If the span of the arch is not more than 8 feet, hollow brick, with 
raised skewbacks, may be used, as shown in Fig. 185. This makes 
a very light and strong floor. | 


274 BUII DING CONSTRUCTION. 


The ¢e-rods for segmental arches should be placed just above the 
bottom flange of the beam, as shown in Fig. 184, and should be pro- 
tected either by special tiling, made so as to form a paneled effect in 
the ceiling, or by wire lathing and plaster. 


Eee aa oat INES 3 5 =.= 9 sa fAS- < = — == ot x 
0 Sefer oe 7 = ys SIT one LEAN S, SCT anny = = 62 I RR 
eee She ; } 3 ae aoe : es 
“~ >, FEA pe perllre —ur ee Se te 
s KEGEL AS 


(Yat) oi las 727 AES age gh gers ac —_ 
No eel A SC 7 Concrete. filling“. 
"i LEMS lp Si rere. Beets 

EY OP res 


Fig. 184. 


Weight and Strength—The following figures may be taken as a fair 
average for the weight per square foot of hollow brick or tile seg- 
mental arches, exclusive of the concrete and plastering : 

Arches 4 inches thick, 20 pounds per square foot ; safe span, 8 feet. 


Arches 6 inches thick, 30 pounds per square foot ; safe span, 16 feet. 
Arches 8 inches thick, 4o pounds per square foot ; safe span, 20 feet. 


The weight of the concrete should be figured for each special case, 
allowing 120 pounds per cubic foot of concrete. Plastering should 
be taken at 8 pounds per square foot. 





The spans for different thicknesses should not exceed those given 
above, except that for spans of 20 feet about 7 feet of the centre por- 
tion may be built of 6-inch tile. 

The segmental form of arch is undoubtedly the strongest that can 
be built, whether of brick, hollow tile or concrete. 

In the celebrated Austrian tests * a common brick arch 54 inches 
thick and 8 feet span, with a rise of 9.85 inches, carried an eccentric 


* Architecture and Building, January 4, 1896. 


FIREPROOFING. 275 


load of 885 pounds per square foot before failing. The failure was 
then caused by buckling and not by crushing. A porous tile arch of 
15 feet 4 inches span, with a rise of 16 inches, built with 6-inch hol- 
low blocks for a distance of 7 feet 8 inches across the centre and 
with 8-inch blocks for the balance, was tested by loading one side 
with a pile of bricks measuring 4 feet 6 inches lengthways of the 
arch and 7 feet 6 inches widthways. When the weight reached 
42,000 pounds (1,235 pounds per square foot) the unloaded side 
commenced to buckle, and in 30 minutes collapsed.* 


Segmental arches, with spans not exceeding those given above, 
built with a rise of 1 inch per foot of span and laid in good 
cement mortar, may be safely relied upon to carry as much as the 
beams, when uniformly loaded. 


Setting.—Segmental arches are set in the same way as flat tile 
arches, except that the centres are arched to the desired curve and 
are suspended at the sides from the beams or girders by hooks pass- 
ing over the beams. The bottoms of the hooks are made round, and 
have a thread and wing nut for bringing the centre into its proper 
place and for lowering it after the arch has set. 


Holes are left where the hooks pass through the arch, and after 
the centres are removed these are subctantially plugged with mortar 
and tile. . 


304. ‘‘Guastavino”’ Arch (Patented, and erected only by R. 
Guastavino).— This is the other type of segmental tile arch referred 
to in the previous section. It is not a true segmental arch, but is 
constructed on the dome principle. 


Arch or dome shells are built of small rectangular tiles of hard terra 
cotta about 6x12 inches and 1 inch thick, cemented together in three 
or more thicknesses, depending upon the size of the vault. The tire. 
are laid on arched centres one course at a time, and each course 
breaks joint with that below. The first layer is usually laid in plas 
ter of Paris and the others in Portland cement. The thickness of 
the shell is generally increased at the haunches or reinforced by a light 
arch sprung against the top of the girder web. Each dome gener 
ally covers the space between four columns, girders being run from 
column to column both ways of the building and tied together at 
their ends. Entire rooms, when surrounded by brick walls and not 
more than 20x4o feet, may also be covered by a single vault. The 





* Enginecring Record, April 14, 1894. 


276 BUILDING CONS OGTTON, 


strength of these vaults, considering their thickness, is very 
remarkable. 

This system does not appear to be applicable to stores and office 
buildings on account of the shape of the ceiling, but for public 
buildings and buildings having solid masonry walls or piers, and 
where a curved soffit is in keeping or desirable, it possesses great 
advantages. It has been used ina number of buildings in New York 
and Boston, and in a few instances in other cities. It was used 
throughout the Boston Public Library. 

305. The Fawcett Ventilated Fireproof Floor.—This 
floor is constructed of dense tile and cement concrete, and differs 
entirely from those previously described. | 

The tiles are tubular in form, and, instead of being made to form 
an arch, are used as lintels, as shown in Fig. 186. They are made 





of fire or chimney pot clay in pieces about 2 feet long. The floor 
beams for this system of construction are spaced 2 feet apart from 
centres, and the lintels are fixed between them with their diagonals 
at right angles with the beams. 

The end of each bay is squared by cutting (during manufacture) 
an ordinary lintel parallel to the diagonal; the piece cut off, when 
reversed, goes on the other end. ‘Thus the ends and sides of all lin- 
tels are open next the walls. These are called “splits.” 

The lintels being in position, specially prepared cement concrete is 
filled in between and over them, which takes a direct bearing upon 
the dottom flange of the beams, thus relieving the lintels of the.floor 
load, which is taken by the iron and concrete, the lintels forming a 
permanent fireproof centring, reducing the dead weight of the floor 
about 25 per cent. and saving about half the concrete. 

The lintels bear on the beams in such a way as to entirely encase 


FIREPROOFING. 277 


the bottom flange without being in contact with it, a clear }$-inch 
space being left for the passage of air. 

The peculiar feature of this system is the circulation of air pro- 
vided through the tubular lintels and under the flanges of the beams. 
Cold air is admitted (through air bricks in the external walls) into a 
portion of the open ends or sides of the lintels, and passes through 
them from bay to bay under the beams, both transversely and longi- 
tudinally of the floor, as shown in Fig. 187. 

It is claimed that the chief fire-resisting agent in this floor is not 
so much the terra cotta or the concrete as the cold air, and that the 
circulation of air through the floor and: around the beams will 
actually prevent the iron from ever getting hot. 

The Fawcett Company claim that their floors have never been 
injured by fire and water beyond what could be repaired by replas- 
tering the ceiling and redecorating the walls. 





The steel floor beams, being spaced so near together, can be made 
very light (5-inch beams being generally used for office floors, 
schools, etc., up to 16 feet span), and as the total thickness of the 
floor from under side of plaster to top of flooring is but 5 inches 
greater than the depth of the beams, the floors are consequently much 
thinner than in almost all other systems. 

The floor is finished on top by bedding 2x3-inch nailing strips in 
the concrete above the steel joist, as shown in Fig. 187, and nailing 
the flooring to these strips in the usual way. 

Repeated tests have proven that the strength of the tile and con- 
crete filling is fully equal to that of the beams, so that the carrying 
capacity of the floor is only limited by that of the beams. For beam 
spans not exeeding 18 feet, the cost of the structural steel work zx 
place does not exceed that of the structural work for the flat arches 
previously described. 

The advantages claimed for this system, aside from its fireproof 


278 BUILDING CONSTRUCTION. 


qualities, are: Saving in height of story from 6 to 8 inches; saving 
in freight, hauling and hoisting, of about 50 per cent. 

No tie-rods are required, and a more even distribution of the floor 
weight on the walls is secured. No centres are required for setting, 
and ordinary unskilled labor can be employed for all portions of the 
work. | 

The weight of the floor is much lighter than that of any other sys- 
tem using tile filling between the beams, with the possible exception 
of the Guastavino floor. 

This floor has been placed in a great many fine buildings in Eng- 
land, and lately in many buildings in Philadelphia and other Eastern 
cities. It certainly has many good points and deserves investigation. 

306. Concrete and Metal Floors.—Within a few years sev- 
eral styles of fireproof floor construction, based upon the use of con- 
crete in combination with iron or steel in various shapes, have been 
introduced in this country, and a few of them have proved strong 
competitors of the hollow tile floor. The chief aim in the introduc- 
tion of these systems has been to obtain a floor that shall have the 
strength and fireproof qualities of the tile floor, and at the same time 
be lighter and less expensive. 

There are two general classes of concrete floor construction. The 
first class consists of tension member floors, which in themselves fur- 
nish the necessary strength for sustaining the floor from wall to wall, 
or wall to girder, without the use of floor beams ; and the other class 
consists of I-beams 5 cr 6 feet apart for sustaining the floor, with 
rods or bars suspended or resting upon the beams, supporting wire 
cloth, netting or expanded metal, which carries the concrete or plas- 
ter filling. Prominent among the first devices mentioned are the 
Hyatt ribbed metal ties and Portland cement concrete floors built by 
P. H. Jackson, San Francisco; the concrete and twisted bar floors 
built by the Ransome & Smith Company, of Chicago; and the Lee 
hollow tile and cable rod floors built by the Lee Fireproof Construc- 
tion Company, of New York. 

Prominent among the I-beam and concrete filling devices are the 
systems of the Metropolitan Freproofing Company, of Trenton, N. J.; 
the expanded metal construction companies of St. Louis and New 
York*the arch construction of the Roebling system and the flat beam 
construction of the Columbian Fireproofing Company. 

While concrete has been used in construction to resist compressive 
stress for many centuries, it was not until 1876 that an attempt was 
made to form concrete beams by imbedding iron in the bottom to 





* For description see page 406. 


FIREPROOFING. 279 


afford the necessary tensile strength which the concrete lacked. The 
idea was conceived by Mr. Thaddeus Hyatt, an inventor, who made 
many experimental beams, with the iron introduced in a great 
variety of ways, as straight ties, with and without anchors and wash- 
ers ; truss rods in various forms, and flat pieces of iron set vertically 
and laid flat and anchored at intervals along the entire length. These 
experimental beams were tested and broken by Mr. David Kirkaldy, 
of London, and the results proved that the iron could be perfectly 
united with the concrete and that it could be depended upon for its 
full tensile strength. 

The method Mr. Hyatt finally adopted as the best for securing per- 
fect unison of the iron and concrete was to use the iron as thin vertical 
blades placed near the bottom of the concrete beam or slab, and ex- 
tending its entire length and bearing on the supports at both ends; 
these vertical blades to be anchored at intervals of a few inches by 
round iron wires threaded through holes punched opposite each other 
in the blades, thus forming a gridiron, which was completely imbed- 
ded in the concrete. 

The first person in this country to make a practical application of 
Mr. Hyatt’s discovery was Mr. P. H. Jackson, of San Francisco, 
Cal., who has used a combination of concrete and Hyatt’s+ties quite 
extensively in that city for covering sidewalk vaults and for the sup- 
port of store lintels ; also for self-supporting floors. 

Tests of concrete beams made by Mr. Jackson are described in the 
Architects’ and Builders’ Pocket Book. 

307. The Ransome & Smith Floor.—While Mr. Jackson 
was experimenting with the Hyatt ties, Mr. E. L. Ransome, a very 
successful worker of concrete in San Francisco, conceived the idea 
of using square bars of iron and steel, twisted their entire length, in 
place of the flat bars and wires used by Mr. Jackson, as shown in 
Fig. 188. It was found that these bars were held in the concrete 
equally as well, if not better, than the other, and that they were much 
less expensive. None of the iron in the ties is wasted, and it has 
been demonstrated by careful experiments that the process of twist- 
ing the bars to the extent desired strengthens the rods instead of 
weakening them. 

Mr. Ransome patented his improvement in 1884, and since that 
time it has been extensively used in San Francisco. 

The Ransome concrete floors are made in two forms—flat (Fig. 188) 
and recessed, or paneled (Fig. 188 A). ‘These floors have been used 
for spans up to 34 feet. No floor beams are required, the floor being 


280 BUILDING CON STRUCTION, 


self-supporting from wa!l to wall (when the building is not more than 
30 feet wide), or from wall to girder. The great strength of these 
floors has been fully demonstrated by actual use in many heavy ware- 






E 
2 eo ENS Sol Usas~ 


Auxilvary ipyeve 


Fig. 188. 





houses in various portions of California, as well as in many other 
buildings. 

A section of a flat floor in the California Academy of Science, 
15x22 feet, was tested in 1890 with a uniform load of 415 pounds per 
square foot, and the load left in place for one month. The deflection 





Fig. 188 A, 


at the centre of the 22-foot span was only finch. It was estimated 
by the architects that the saving by using this construction throughout 
the building, over the ordinary use of steel beams and hollow tile 
arches of the same strength, and with similar cement-finished floors 
on top, amounted to fifty cents per square foot of floor. 


FIREPROOFING. 281 


The flat construction shown in Fig. 188 is the best adapted, of the 
two, for office buildings, hotels, etc., although the paneled floor, 
shown in Fig. 188A, has much the greater strength for the same 
amount of material. The latter construction has been used in sey- 
eral warehouses in California without the use of any steel or iron 
beams or girders, and has supported very heavy loads for several 
years. 

As a fireproof construction this system is undoubtedly equal to any 
other construction in use. The patents controlling the use of twisted 
bars in combination with concrete are now owned by the Ransome 
& Smith Co., of Chicago, from whom more complete information 
of their system of flooring may be obtained. 

308. The Lee Hollow Tile and Cable Rod Floor.— — 
Mr. Thomas A. Lee, the originator of the end system of hollow tile 
arches, about the year 1890 patented a system of floor construction 
which is the same in principle as the Ransome floor. Instead of 


Cement Floor 





Fig. 189.—Lee Floor. 


using concrete to resist the compressive stress, hollow porous tile 
blocks with square ends and a rod groove along one side near the 
base are used, as shown in Fig. 189. The tension member con- 
sists of cables made of round, drawn steel rods of about 5%; of an 
inch in diameter laid spirally together, usually in two strands. The 
rods are spaced 8, ro or 12 inches apart, according to the span and 
width of tile, and are buried in soft Portland cement placed in the 
grooves near the bottom of the tile. The cement unites the tiles and 
cables so as to form a composite beam. The floors extend like a 
flat plate from wall to wall, or from girder to girder, their thickness 
being about % inch for each foot of span. 

- Floors and roofs similar to the above have been built in various 
_ costly buildings in different portions of this country and in Canada, 
the spans varying from ro to 28 feet. 

In buildings having solid brick or concrete walls and partitions, 
these tension member floors may be used to good advantage, but it is 
doubtful if they ever come into general use in buildings built on the 
skeleton principle. They require very careful and faithful workman- 
ship and the very best quality of cement to make them safe. 


282 BUILDING CONSTRUCTION. 


309. The Metropolitan Floor.—This floor, which was fora _ 
time known as the “ Manhattan” system, and is protected by letters 
patent, 1s constructed as follows: Cables, each ccmposed of two gal- 
vanized wires (usually of No. 12 gauge) twisted together, are sus- 
pended between the top of I-beams, as shown in Fig. 190, and spaced 
from 1 inch to 14 inches apart, according to the load which is 
to be carried. ‘The ends of the cables are secured to the beams by 
means of hooks 3 inches long made of }-inch square iron, which 
grasp the upper flange. A length of gas pipe is laid over the cable 
midway between the beams to give them a uniform sag. Forms or 
centres are then placed under the cables, and a composition consist- 
ing of 5 parts, by weight, of plaster of Paris and 1 part of wood shav- 
ings, mixed with sufficient water to make a thin paste, is poured on. 





Fig. 190. 


As plaster of Paris sets very quickly the resulting floor is sufficiently 
strong to be used at once under loads, with a surface uniform and 
level above the top of the beams. 

Where a paneled ceiling can be used wire netting is stretched over 
the beams and the same composition poured around them, fireproof- 
ing the beam, as shown at J, Fig. 191. Where a flush ceiling is 
required flat bars are placed on the bottom flanges of the beams and 
wire netting stretched over them. Forms are then placed under- 
neath and the same composition as in the floor plate poured on, form- 
ing a plate about 1} inches thick and extending r inch below the bot- 
tom of the beams, as shown at 4, Fig. rot. 

The usual thickness of the floor plate is 4 inches, with beam spac- 
ings of from 4 to 6 feet. It will be seen that in principle this floor 
closely resembles the Ransome tension bar system, as the cables take 
up the tension and the concrete resists the compressive stress. This 
combination of steel (in its strongest shape) with concrete is theoret- 


FIR EPROOFING. 283 


ically one of the most perfect forms of fireproof construction, and 
although defects may be discovered in the details of construction, 
the system itself seems destined to become of wide application. 

No tie-rods between the beams are required in this system, as the 
floor plate is practically a beam, and transmits only a vertical pres- 
sure to the I-beams. 

The tests that have been made of this floor construction seem to 
prove. that it is thoroughly fireproof and heat-resisting, and that its 
ultimate strength for floor plates 4 inches thick and 6 feet span is 
about 1,500 pounds per square foot, while loads as high as 2,000 
pounds have been supported by it. 

The remarkably light weight of this floor is one of its chief advan- 
tages, the average weight of the floor plate being about 18 pounds 
per square foot, and the weight of the ceiling plate, without the plas- 
tering, 6 pounds. A floor constructed by this method with I-beams 








Fig. 191. 


6 feet apart would therefore weigh, when all complete and ceiling 
plastered, less than half as much as the old style dense tile systems. 

The greatest objection thus far brought against this fioor is the 
great amount of water used in its construction and the time required 
for the wood shavings to dry out. 

310. Mr. J. Hollis Wells, C. E., in reviewing some tests of fire- 
proof floors made at Trenton, N. J.,in 1894, makes the following 
comparison between the concrete and wire and hollow tile floors: 
“The method of suspending a fireproof material on wires of proper 
strength from beam to beam makes a strong homogeneous floor, 
absolutely fireproof, and each bay or section independent of those 
adjoining. The hollow tile arch, creating a thrust on the floor beams, 
depends on tie-rods to counteract it. Tie-rods seldom set in proper 
place, oftentimes are not screwed up tight, and the construction is 
weakened. In the suspended floor tie-rods are not used at all ; beam 
is tied to beam from upper flange to upper flange, and a rigid base 
extends clear across the floor from wall to wall.” * 





* Engineering Record, December 22, 1895. 


284 BOITDING CONSTRUCTION. 


Various styles of floors have been constructed on the principle of 
the Metropolitan floor, although nearly all use Portland cement con- 
crete instead of the plaster composition. Wire lathing, expanded 
metal, and various shaped bars are used for the tension members. 

The principal advantage sought in these floors over the terra cotta 
tile arches is a reduction in the weight of the floor, thereby causing a 
saving in the steel construction. The floors themselves are also, asa 
rule, a little cheaper than the tile floors. 

The strains in floors of this kind are the same as in those of a beam, 
the effect.of the load being to pull the tension members apart at the. 
bottom and to crush the concrete on top. When the concrete is of 
the proper thickness, and of good quality, the strength of the floor 
will be determined by the strength of the tension members. 

Several tests’ of beams made of Portland cement, concrete and wire 
netting made by the New Jersey Wire Cloth Company, appear to 
show that only about one-half the strength of the tension members 
(when of wire cloth) can be developed. In all floors constructed of 
concrete, plaster or tile, with steel tension members, it is of the first 
importance that the two materials shall be so closely united that the 
tension members will not be drawn through, or slip in the concrete, 
for the minute this occurs the strength of the floor, as a beam, is 
destroyed. ‘To secure this perfect adhesion, 1t is necessary that the 
materials and work shall be of the best quality and not slighted in 
any way. 

311. The Roebling Patent Fireproof Floor. *—This also 
is a concrete construction, but the concrete, instead of being used as 
a beam, is entirely in compression, the strength of the floor being due 
to the resistance of the concrete acting as an arch. 


The method of forming the floor and ceiling is well illustrated by 
Fig. 192. The floor construction consists of a wire cloth arch, stiff- 
ened by steel rods, which is sprung between the floor beams and 
abuts into the seat formed by the web and lower flange of the I-beams. 
On this wire arch Portland cement concrete is deposited and allowed 
to harden, making a strong-monolithic arched slab between the. 
beams. The ceiling construction consists of supporting rods attached 
to the lower flanges of the floor beams by a patent clamp, which off- 
sets the rods below the I-beams. Under these rods, and securely 
laced to them, is placed the Roebling standard lathing, with the 
stiffening rods crossing the supporting rods at right angles. This 





* Controlled by the John A. Roebling’s Sons Co. 


FIREP ROOFING. 285 


construction produces a ceiling that is uniformly level over its entire 
surface, requiring the same amount of plaster over all portions. The 
_ ceiling being separate from the floor is not liable to stains, as is fre- 
quently the case with tile construction. 

The weight of finished floor and ceiling, including the plastering 
underneath and two thicknesses of wood flooring, as given by the 
Roebling Co., varies from 28 to 53 pounds per square foot, according 
to the span and depth of beams or girders. This is exclusive of the 
steel beams. [See also page 405.| 

The strength of this floor depends, of course, almost entirely upon 
the concrete—the quality and proportion of the ingredients and the 
mixing. 


PERO 


Z Zz PO ae 

CSS 

= 
Za SEER PRL 


AIR SPACE 
UNDER GEAM 





Fig. 192. 


Thus far, where the system has been used, only the best grades of 
imported Portland cement and the best sharp sand have been used. 
For dwellings and buildings in which the live load never exceeds 100 
pounds per square foot, a concrete made of cement, sand and first- 
class cinder may be employed, with a saving in weight and cost, and 
at the same time with ample strength. 

Various tests of these floors built by the Roebling Sons’ Co., with 
spans varying from 44 to 5 feet, have shown a carrying capacity, wth 
no signs of fatlure, of from 1,000 to 2,400 pounds per square foot.t 
Further evidence of the strength of such floors is also furnished by 
the celebrated “ Austrian’”’ tests on concrete arches.* In these tests 
a concrete arch only 3 inches thick and span of 44 feet, without 


* See Architecture and Buildin, January 4, 1895. + See also page 405. 


286 BUILDING CONSTRUCTION. 


filling above the haunches, sustained 1,638 pounds per square foot 
over the entire area without failure or cracking, while a similar arch, 
332. inches thick, with span of 8 feet 10 inches and rise of 104 inches, 
sustained an eccentric load over one-half of the arch of 1,130 pounds 
per square foot. The arch then failed by duckling, and not by com- 
pression. 

The strength of the Roebling floor, therefore, may be considered 
ample for any load that may be applied, provided the concrete is of 
sufficient thickness at the crown and of good quality. 


The most economical proportions for this floor, considering also 
the cost of the steel beams, will generally be obtained by using 
to-inch I-beams, spaced as far apart as the loads will permit. 


Aside from its strength and fireproof qualities, this construction 
possesses many practical advantages, a few of which may be briefly 
mentioned: A perfectly flat ceiling, which may be placed any dis- 
tance below the beams and which is not hable to discoloration; a 
continuous air space between floor and ceiling; it is much lighter 
than many of the tile floors, and can be adapted to any building or 
to any load. The ceilings may be either flat, paneled or arched. 


No special arrangement of floor beams is required, and the spac- 
ings need not be uniform. 


The floor is not eastly damaged ; openings of any size may be cut 
through the concrete to neat dimensions, the wire cloth preventing 
the concrete from flaking away on the under side. 


Where buildings must be erected with great rapidity, or in winter 
weather, this system is especially desirable. No wood centring is 
required, and as the arch wire is made to dimensions and bent to the 
correct curve at the mill, the wire arches can be put in place very 
quickly and in eny kind of weather. Once in place they afford a 
protection to workmen, as they possess sufficient strength in them- 
selves to sustain a considerable load, or to intercept a person falling 
from the beams above. The wire arches are generally set so as to 
keep within two stories of the masons. As Portland cement is used 
for the concrete, the latter can also be safely mixed in quite cold 
weather. ‘The floors are safe and available for use two days after the 
concrete has been applied. 

The cost of this system should not exceed that of other systems 
using Portland cement or tile, and in many instances would probably 
be less. 


FIREPROOFING. 287 


312. The ‘‘Columbian” System of Firenroof Floors.*— 
This system is also one of concrete construction, the shape of the con- 
crete being very much the same as in the Metropolitan floor. In this 
floor, however, the concrete, instead of being supported by wires or 
netting, is supported by ribbed steel bars of a special shape, suspended 
from the steel I-beams and supported on edge by means of steel stir- 
rups, which have the profile of the bar cut in them, as shown in 
Fig. 193. After the bars are set in place a wooden form is suspended 
beneath them and a layer of Portland cement concrete is laid on top, 
flush with the top of the beams and completely surrounding the 
ribbed steel bars. 


If a level ceiling beneath the beams is desired it is constructed 
independently of the floor by using 1-inch section ribbed bars, resting 
on the bottom flanges of the 
I-beams, and filling between 
.and around them with con- 
crete, in the same way as is 
done for the floors. 


The system of floor and 
ceiling construction is plainly 
shown by the section drawing, 
Fig. 194. 

Three sizes of bars are used 
for the floor construction— 
2k-inch, 2-inch and 14-inch, 
and these are spaced at different distances apart, according to the 
span and the weight to be supported. The 24-inch bars are used only 
in warehouses, heavy storage buildings, etc.; the 2-inch bar for floors 
in office buildings and where the loads do not exceed 200 pounds per 
square foot. The 14-inch bar gives sufficient strength for floors in 
residences, apartment houses, etc. The shape of the 2-inch and 
24-inch bars is shown by the hole in the stirrup, Fig. 193. The 
1$-inch bar has only one rib. The stirrups are made of 2x;-inch 
steel. The usual spacing of the bars is about 20 inches. 





Fig. 193. 


The concrete recommended by the Columbian Co., and generally 
used, is composed of 1 part Portland cement, 2 of sand and 5 of 
crushed furnace slag, although broken brick and certain kinds of rock 
are also sometimes used. 


The most economical spacing of the floor beams for this construction 





* Patents controlled by the Columbian Fireproofing Co. 


288 BUILDING CONSTRUCTION. 


is 6 feet from centre to centre of beams for the double construction 
shown in Fig. 194 and 7 feet for paneled construction, although either 
construction can be adapted to spans up to 8 feet. It is also not 
necessary that the spacing of the beams be uniform, and no special 
framing is required for this system, as it can be readily adapted to 
any plan suitable for any of the flat floor constructions described, 
although with this system the beams can often be made lighter or 
spaced farther apart, owing to the decreased dead weight of the floor. 


In most classes of buildings other than offices and dwellings the 
double construction is not necessary, as the bottom of the floor 
construction answers for the ceiling, and by enclosing the beams and 
girders with concrete or tile, a neat paneled effect is produced, and 





the height of the story increased or the total height of the building 
decreased, as preferred. 

Fig. 195 shows two styles of girder casings used in connection 
with this system, both providing for an air space completely around 
the steel. The casing shown at 4 is made of concrete slabs, sup- 
ported by iron clamps or ties, which are completely imbedded in and 
insulated by the bottom slab—a very important provision. The cas- 
ing shown at Z is made of hollow tile, thus providing two air spaces 
on each side of the beam and one underneath. Concealed anchors 
are also used for this casing. 3 

This floor may be finished on top in the usual way by imbedding 
nailing strips in cinder filling, or 2}x1}-inch strips (not beveled) may 
be nailed directly to the concrete floor and the filling omitted. Nail- 
ing strips have been applied in this manner in several large build- 
ings, and, it is claimed, with the best results. 


FIREPROOFING. 289 


The weight of this system of floor construction, exclusive of the 
I-beams, plastering, nailing strips and flooring, is as follows: 


For 2}-inch bars, 4 inches of concrete, 40 pounds per square foot. 
For 2-inch bars, 3 inches of concrete, 30 pounds per square foot. 
For 1}-inch bars, 2} inches of concrete, 24 pounds per square foot. 


The level ceiling shown in Fig. 194 (2 inches thick) weighs 20 
pounds per square foot. 

Strength.—The Columbian Co. ‘guarantee that their 3-inch floor, 6 
feet span, will support 200 pounds per square foot; the 4-inch floor, 
6 feet span, 600 pounds per square foot, and the 24-inch floor, 5 
feet span, 150 pounds per square foot, wth factor of safety of four, 
and the published tests that have been made of this system would 














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B 


Fig. 195. 


appear to sustain the guarantee. This construction appears to be 
especially strong to resist drop or jarring loads. A ram weighing 238 
pounds was dropped from the height of 8 feet on the centre of an 
8-foot span several times without perceptible effect on the floor. (The 
bars in this floor were 24 inches, spaced 20 inches apart.) It is also 
claimed that in case of overloading the floor will not fail suddenly, 
but that the bars will gradually bend, thus giving warning of danger. 

The complete fireproof quality of this floor, which is, of course, 
the same as that of the Roebling and other Portland cement floors, 
was proved by a severe test of fire and water while the floor was uni- 
formly loaded with 750 pounds per square foot. 

Economy.—While this floor is thoroughly fireproof and waterproof 
and possesses ample strength and remarkable rigidity, it also possesses 
several advantages of a practical and economical nature. 


290 BUILDING CONSTRUCTION. 


No tie-rods are required, and no punching of the I-beams is nec- 
essary, except where they are framed to the girders or around open- 
ings. Lighter beams may be employed than where heavier types of 
floor construction are used. No channels are required in outside 
masonry walls. 

In buildings having brick partitions and solid masonry walls this 
floor, with paneled ceiling, is especially economical, as no channels 
are required, and the beams require no punching, except for anchor- 
ing their ends to the walls. This floor can be constructed as rapidly 
as any and can be carried out without difficulty in winter weather. 

Holes may be cut at any place in the floor by plumbers or electric- 
ians without injuring the strength of the floor, and the holes may be 
cut as small or as large as may be necessary. 

312. Actual Weight of Fireproof Floors.—In the spring 
of 1895 a series of fireproofing tests was made in the basement and 
first story of a building then being erected in Boston, a full descrip- 
tion of which may be found in the American Architect of Septem- 
ber 7, 1895. 

The question of the comparative weights of the different floor con- 
struction having been raised, it was decided to weigh a section of each. 

The debris from the fires was removed from the houses, the floors 
broken down, care being taken to preserve all the material that had 
entered into their construction, and it was then weighed on platform 
scales. The data thus gathered are tabulated below. 











— 


AREA OF TOTAL | WEIGHT PER 








Ano eee SE ecar SECTION. WEIGHT. | SQ. FT. 
i Roebling Systems, 7. 2.40) belo podrtt. 1,295 lbs, 72° lbs, 
2. Metropolitan System, panel 

CONSITUCHION Gece steree 18 4, 427: 23.7 es 
ee Expanded Metal Co.’s Sys- 

Pee ore ot oe eee ae ay A O07 me: 95.Ae 
32 |Same as No. 3, with addi- 

tional flaticeiling. .....1. 2255 ei Loi4eec 80/055" 
4. Bareks oy suetirre st 2 cates ete 20.25 ‘‘ *r1;604558.° 85.3 
5. 12-inch porous hollow tile 

arch blocks covered with 

concrete 2 inches thick..| 20.25 ‘‘ pikes ey 87.95 * 





In considering this table it should be noted that all of the floors, 
with the exception of No. 2, were plastered on the under side, and were 


FIREPROOFING. 291 


concreted on top, ready to receive the wocd floors. The plastering 
on No. 5 fell during the fire test and was removed with the debris, 
and, consequently, not weighed with the other material; the weight 
of the 12-inch floor beams is not included in the weight given above. 


313. Selection of a System.—Where there are so many styles 
of fireproof floors, each claiming to be superior to the others, it is dif- 
ficult for the architect to decide on a particular construction. The 
choice of a system of fireproofing is more apt to be decided by the 
question of cost than by other considerations. The relative cost of 
different systems will also vary somewhat with the locality and dis- 
tance from the manufacturing centres. It should be ascertained, 
before fully deciding on the system to be used, by obtaining approx- 
imate bids from the different fireproofing companies, most of whom 
are always ready to submit such bids. 


The author believes that either of the floor systems described 
herein, if properly constructed with materials of good quality, will 
make a thoroughly fireproof floor, although where the danger from a 
severe conflagration is especially imminent, porous tiling is generally 
considered as the superior non-conducting material. 


The question of strength hardly needs to be considered except for 
floors for warehouses and heavy storage buildings, as either of the 
systems possess sufficient strength for other buildings if the sections 
are not made too light or the spans too great. 


- Where heavy loads are to be carried, however, those systems which 
have uniformly developed the greatest strength should be selected. 
The question of lightness is often one of considerable importance, 
especially in dwellings, apartment houses, hotels and office buildings. 
Very often the considerations of speed in erection and quickness in 
drying out, the adaptability to putting in place in cold weather, etc., 
are sufficient to decide in favor of a particular system. 


Many engineers still favor the use of dense or porous tiles for fire- 
proofing, and these materials are undoubtedly of great value, and 
possibly the best for certain conditions, but the combinations of iron 
with Portland cement concrete are rapidly gaining in favor, and the 
author believes that concrete, when properly combined with the 
metal, makes a very strong and thoroughly fireproof construction, 
and that it has now been used for a sufficient length of time to fully 
demonstrate its adaptability to floor construction. 


With nearly all systems of fireproofing the efficiency of the con- 
struction depends very largely upon the character of the workman- 


292 BOULLDING (CON Sa RUG aC 


ship and the quality of the materials used. When it is desirable to 
use as much unskilled labor as possible, the Fawcett, Roebling or 
Columbian floors can be used to advantage, an intelligent and honest 
foreman being the only skilled person required. 


FIREPROOF ROOFS. 


314. Flat Roofs.—Nearly all fireproof office buildings, apart- 
ment houses, hotels and warehouses have “flat’’ roofs, pitched just 
enough—generally from + to $ an inch to the foot—to cause the water 
to run to the lowest point. It is easier to make a flat roof thoroughly 
fireproof than it is a pitch roof, and the flat roof is also much less: 
expensive. 


The usual, and also the best, method of constructing flat roofs on 
fireproof buildings is to build the roof in the same way as the floors, 
giving the beams the same pitch as the roof. If the filling between 
the beams is of hollow tile, segmental arches, or flat arches with raised 
skewbacks, may be used with economy. 


When any of the patented systems of fireproof construction is used, 
the roof, if flat, is almost invariably constructed in the same way as 
the floor, only using a little lighter section. 


After the filling between the beams is set, the roof should be cov- 
ered with cement mortar or concrete, sufficient to bring it to a uni- 
form surface and to give the desired pitch. 


The roofing may be either of tin, copper, rock asphalt or compo- 
sition, finished on top with gravel or vitrified tile set in Portland 
cement. Coal tar, pitch and asphalt have a natural affinity for 
cement or terra cotta, and adhere readily to them without the use of 
fastenings. If a tin or copper covering is to be used, porous tiling is 
especially adapted for the beam filling, as the nails for the tin cleats 
may be driven directly into the tiling. Before applying the tin the 
entire surface of the roof should be plastered smooth with ? of an 
inch of cement mortar to form a smooth, hard surface on which to 
hammer down the tin. Thin, hollow tiles, set between 3x3-inch 
T-irons, are also occasionally used for roofs. 


Whatever kind of tiling or filling is used it should be of such con- 
struction that the bottom flanges of the beams or T-irons will be well 
protected, and if tiling is used it should receive a heavy coat of plas- 
ter under the beams, if not elsewhere. The supporting girders and 
columns should also be well protected, either with hollow tiles, con- 
crete or plastering on metal lathing. 


FIREPROOFING. 203 


315. Mansard and Pitch Roofs.—For mansard roofs the most 
economical method of construction is by using I-beams, set 5 to 7 feet 
apart, and filled in between with 3-inch hollow euec cs tile, provis- 
ion for nailing slate being made by attaching 1}x2-inch wood strips 
to the outer face of the tile, the strips being set at the proper distances 
apart to receive the slate, the spaces between the strips being then 
plastered flush and smooth with cement mortar. In case of a severe 
conflagration the slate would probably be destroyed, and the wooden 
strips might be consumed, but the damage could go no farther. In 
place of partition tile porous terra cotta bricks or blocks may bé used 
for filling between the I-beams. For roofs where the pitch is not 
over 45°, 3x3-1nch T-irons, set 16 inches between centres and filled in 
with slabs of porous terra cotta, make a very desirable roof. If slates 
or roofing tiles are used they may be nailed directly into the porous 
tiles, or, if it is desired to use hollow tile, strips of wood may be 
nailed to the tile for receiving the slate and the spaces between the 
strips filled in with cement. 

All truss members, purlines, etc., should be protected from fire and 
heat either by wire lathing or by porous tiling, covered with a heavy 
coat of plaster. Probably the best and most thorough method of 
protecting truss members is by first covering them with 14-inch slabs 
of porous tiling and wrapping them securely with wicened wire lath- 
ing, which should then be covered with a heavy coat of cement plaster. 

316. Ceilings.—In office buildings having a flat roof there is gen- 
erally an air space or attic between the roof and ceiling of the upper 
story, varying from 3 to 5 feet in height. This space is often utilized 
for running pipes, wires, etc. Buildings having pitched roofs neces- 
sarily require a ceiling below 1o give a proper finish to the rooms 
in the upper story and to make the rooms comfortable. In office 
buildings the ceiling under the roof is generally of a similar construc- 
tion to that of the floors, although when systems like the Roebling, 
Columbian or Metropolitan are used in the building only the sus- 
pended ceiling plate is required between the beams, and the latter 
may be made very light. 

Under pitch roofs (and sometimes under flat roofs) a suspended 
ceiling is generally used. T-bars (usually 3x3 inches in size) are hung 
from the roof construction by means of light rods, and the ceiling 
constructed either by means of wire or expanded metal lathing laced 
to light angles, or flat bars placed between the T’s, or by thin tiles of 
dense or porous terracotta. If a tile ceiling is to be used, the author 
believes that porous or semi-porocus terra cotta should be given the 


294 BOILDING COM Sd RUCTION. 


preference. Whichever material is used, the shape of the tiles should 
be such that they will drop below the flanges of the T’s, so as to pro- 
tect the metal. 

Fig. 196 shows the usual section of porous ceiling tile, and Fig. 197 
an improved shape of semi-porous ceiling tile made by the Pioneer 
Co. The width of the porous tile is 16 inches for 2-inch tile and 18, 
20 and 24 inches for 3-inch tile. The 2-inch tiles weigh 11 pounds 





Fig 196. 


and the 3-inch tiles 15 pounds per square foot, exclusive of the plas- 
tering. The tiles shown in Fig. 197 are 3 inches thick and weigh 
144 pounds per square foot. 

Suspended ceilings of wire lath and plaster weigh only about 12 
pounds per square foot, including the plastering. 

Whether tile or metal lathing is used for the ceiling, the webs of 
the T’s should be covered with plaster or cinder concrete, to protect 
them from heat. 

317. Girder and Column Casings.—The columns and gird- 
ers are more exposed to intense heat than the floor beams, and should 
be protected in the most efficieit manner possible, as any expansion 
in the columns or girders would have a most disastrous effect. 


Se Oe 


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ZZZii22aea) > xX 3 


CLZZIRZLL2 pad 
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g Ae 
ZIZL ALLL] 


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Fig 197. 


Columns and girders are also more exposed to the streams of water, 
which tend to dislodge or break through the casing. Asa rule, the 
manner in which these portions of the structural work are protected 
depends largely upon the system of floor construction employed. 
Naturally the parties having the contract for the fireproofing of the 
floors generally wish to use their system, or materials, for protecting 
the columns and girders, and thus the question of cost often works to 
the disadvantage of the better system. 

In buildings with tile filling between the floor beams the columns 
and girders are usually cased with tiles; when one of the concrete 


FIREPROOFING. 295 


systems of floor construction is adopted, the same material is, as a 
rule, employed for protecting these members, although there is no 
necessity for using, the same material in both cases. 

The unbiased opinion of architectural engineers and those who 
have made a study of fire protection is, the author believes, in favor 
of solid porous tiling for girder and column casings. The author 
believes that the best possible protection for these members will be 
obtained by using solid blocks of porous terra cotta, well secured to 
the metal, and then covered with wire or expanded metal lathing 
plastered with hard mortar, such as “ Acme’ or “ King’s Windsor,” 
the metal lathing serving principally as a protection from the blocks 
becoming dislodged. 

Girders.—The usual forms of dense or porous tile casings for gird- 
ers are shown in Fig. 198. Shapes very similar to these are made by 


FLOOR |. BEAMS 





Fig. 198. 


all the manufacturers of both dense and porous tiling. Casings of 
dense tiling should preferably be made hollow, thus giving a second 
air space, as shown in Fig. 195, 4. Methods of casing girders with 
metal lathing will be shown in Chapter XI. 

318. Columuis.—The protection of the columns, especially in a 
very high building, should be considered as the most important por- 
tion of the fireproofing, although in too many cases it is slighted even 
to a dangerous extent. The Chicago building ordinance is quite 
explicit in its requirements for the protection of columns, and forms 
- a good guide for architects elsewhere to follow. These requirements 
_ are as follows: 


Sec. 108. In the case of buildings of Class I. the coverings for columns shall be, 
if of brick, not less than 8 inches thick ; if of hollow tile, these coverings shall be in 
two consecutive layers, each not less than 25 inches thick. If the fireproof covering 
is made of porous terra cotta, it shall consist of at least two layers not less than 2 
inches thick each. Whether hollow tile or porous terra cotta is used, the two con- 
secutive layers shall be so applied that neither the vertical nor the horizontal joints 


296 BUILDING CON SLROCTION. 


in the same shall be opposite each other, and each course shall be so anchored and 
bonded within itself as to form an independent and stable structure. 


SEc. 109. In places where there is trucking or wheeling or other handling of 
packages of any kind, the lower 5 feet of the fireproofing of such pillars shall be 
encased in a protective covering either of sheet iron or oak plank, which covering 
shall be kept continually in good repair. 


Sec. 111. In buildings belonging to Class II. the fireproof covering for internal 
columns is to be made the same as specified for the buildings of Classes I. and IV., 
excepting only that but one covering of hollow tile or porous terra cotta, and but 
two layers of any covering made of plastering on metallic lath, are to be used. 


The most common and cheapest method of fireproofing interior 
columns has been through the use of shells of dense terra cotta sur- 
rounding the column, the separate tiles being usually clamped or 


hooked together, but not to the 
I . 
2 Porous Tile 


metal work. This method has 
SLL zzzn2z2rzrdee not proved altogether successful. 

\ a) “The use of dense tiles is only 
to be recommended when such 
tiles are hollow, with a proper 
air space around the metal col- 


Ny = umn, and even then experience 
NS 





ITLL LS seems to show that the hard tile 


HollowBrick incemen 


is.1n no way as satisfactory under 
great heat as the more porous 
kincdss 3. 

Solid blocks of porous tiling at 
least 2 inches thick, well bedded against the metal column and 
secured by copper wire wound around the column outside of the cas- 
ing, seems to be the most approved method of insulation. 


c 


Fig. 199. 


The custom has been quite general of running the water and gas | 
pipes beside the metal columns and inside the fireproof casing. 
When this is done the protection at the floors is often very imper- 
fectly made, and the custom is not now approved. 

The best method of running and concealing the pipes is that shown 
in Fig. 199, which represents the fireproofing of the columns in the 
first eight stories of the newer portion of the Monadnock Building in 
Chicago. 

Fig. 200 shows a few of the best shapes of dense tile covering. 
The tile shown at A may be used for any size or shape (except 
round) of column by varying the width of filling pieces a. 


* Joseph K. Freitag, C E., in Architectural Engineering. 


FIREPROOFING. 207 


Columns are also occasionally protected by surrounding them with 
a thick coating of concrete. When the concrete is formed in place 
so as to make a monolithic shell, extending 3 or 4 inches beyond the 
metal, this should make a very efficient protection. 

Methods of protecting columns by metal lathing and plaster are 
described in Chapter XI. 

319. Partitions.—The partitions in fireproof buildings should be 
built either of brick, tile or iron studding, covered with metal lath 
and plaster. Brick partitions, when not less than 12 inches thick, 
may be considered as fireproof, but they are now seldom used except 
where they can be utilized to support the floors. 

In the modern fireproof office building, hotel or apartment house 
the floors are supported, except at the walls, entirely by columns and 
girders, and the partitions are almost universally constructed either 






























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of hollow tile, or of thin, solid porous tiles, or metal lath and plaster. 
Hollow tile are probably the most extensively used for this purpose, 
although “thin” partitions (from 14 to 2 inches thick) are coming 
into quite general use in office buildings. 

Partition tiles are made of the same materials and possess the same 
characteristics as those used in floor construction. Both dense and 
porous tiles are used for this purpose, porous tiles probably the most 
extensively, owing to their property of receiving and holding nails. 

Partition tiles are made in thicknesses varying from 2 to 6 inches, but 
the 4-inch blocks are most commonly used. ‘The tiles are generally 
12x12 or 6x12 inches on the face. They may be set with the hollows 
running vertically or horizontally, either construction being sufficiently 
strong; the horizontal construction, however, has the advantage of a 
better bonded mortar joint. When the tiles are laid vertically they 
are frequently clamped together; when laid horizontally a certain 


298 BUILDING CONSTRUCTION. 


number of tile should be set vertically to accommodate the gas pipes. 
When the latter are located before the partitions are set the tile may 
be cut and built around the pipes, or special recessed tile may be 
used, as shown in Fig. 201. Whether laid vertically or horizontally, the 
blocks should always be set so as to break joint with each other. 

; For setting the tiles or blocks, 
lime mortar, to which a small 
proportion of natural cement is 
added, is generally used. Acme 
cement plaster has recently 
been used for this purpose with 
excellent results, as it adheres 
to the tiling even better than 
natural cements. 

At all openings in partitions 
rough wood frames are set, as 
shown in Fig. 202, to stiffen the 
jambs and to afford grounds for 
the plaster and nailings for the 
finished frames and casings. 

If dense tiles are used for the 
partitions it is necessary te 
build in wooden bricks or 
4-inch strips in the horizontal or vertical joints to form nailings for 
the base, chair rail and picture moulding, or courses of porous tiles 
may be inserted at these places. When porous tiles are used the 
wood blocks or strips are generally omitted, although experience has 
shown that porous tiles do not hold the nails quite so securely as wood. 

Hollow tile partitions are generally 
laid on top of the finished floor if there 
is the least likelihood of their ever 
being taken down, and, as they are not 












pa HS at 

CY a SS Door 

ATile Yani 
LEE \ 





‘ 


iN 
i 





fastened in any way to the floor or ceil- a ee 
rery easl ren r 
ing, they can very easily be removed o noes 


changed to suit tenants. 
The weight of hollow tile partitions per square foot, plastered both 
sides, will average as follows: 


3-mch dense tile. .... : 27 pounds. 3-inch porous tile...... 24 pounds. 
4-inch dense tile...... 29 pounds. 4-inch porous tile...... 29 pounds, 
5-inch dense tile...... 32 pounds. 5-inch porous tile...... 35 pounds, 


6-inch dense tile...... 36 pounds. 6-inch porous tile...... 39 pounds, 


FIREP ROOFING. 299 


320. Thin Partitions.—In order to economize the floor space 
as much as possible, devices have been introduced for constructing 
partitions that, when plastered both sides, will be only from 1} to 2? 
inches thick. Such partitions are now commonly designated as 
“thin” partitions. There are a number of devices for constructing 
thin partitions, nearly all of them using 1$-inch steel studding, to 
which expanded metal or wire lathing is applied, and sometimes bur- 
lap. These constructions are generally erected by the plasterer, and 
will be described in Chapter XI. 

Henry Maurer & Son have patented a partition made of 2-inch 
blocks of solid porous terra cotta, each block being connected to the 
other by a galvanized iron clamp. The bottom and top courses are 
also secured to the floor and ceiling by means of a galvanized iron 
shoe. No other supports in the shape of ironwork are necessary, and 
it is ctaimed that the partition is very stiff. The blocks can be put 
up by either carpenter or mason. The thickness of the partition, 
when plastered both sides, is 3 inches, and the weight per square foot, 
including plastering, 20 pounds. 

The Lee Construction Co. also have a patented thin partition, which 
is made of exceedingly light and porous plates of porous tiling, with 
tension rods of twisted steel wires placed on each side and imbedded 
in the plaster. Nostudding is used. The tension rods, being on the 
outside of the partition, make the partition very stiff and perfectly 
straight. This partition is made by the Lee Co. and plastered one 
coat with hard-setting plaster, such as “Acme” or “‘ Windsor,”’ so 
that only the finishing coat of plaster need be applied by the plas- 
terer. The Lee Co. also supply and set the rough frames for doors 
and side lights, and build in all nailing blocks for the base, chair rail 
and picture mould. The thickness of this partition when finished is 
2 inches for stories 13 feet high, 24 inches for stories from 13 to 15 
feet. 3 inches for stories 15 to 18 feet and 4 inches for stories 20 feet 
high. This partition was used throughout the fifteen-story Syndicate 
Building in New York City. 

321. Wall Furrings.—It is generally customary to fur the base- 
ment walls of fireproof buildings, and occasionally the walls above, 
with tile blocks made for this purpose. 

The most common shape of furring tile is that shown in Fig. 203, 
the blocks being 12 inches square and 2 inches thick, although fur- 
ring tile are made 14 inches thick, and in both larger and smaller 
sizes. They are also made of both dense and porous tiling. The 
latter possesses the advantage that nailing strips are not required, 


300 BULL DING CON STIG CLIOLY? 


but it is doubtful if they offer as good protection from moisture as 
the harder burned fire clay tiles. 


The tiles are laid against the walls in ordinary lime and cement 
mortar with broken joints, the hollows always running vertically. 





Fig. 203. 


Flat-headed nails are driven at the joints into the brickwork to 
secure the tiles until the mortar has set. When dense furring tile are 
used, 4-inch strips of wood should be laid in the joints, either vertical 


iy BRICK WALL. Wy 
YY Yi 


2a teres ar: = 
NI 







Nk C2 





NEY f Ea 

= TSS SA Nec a Santer ESS ASSSS 
‘ ie > Fei . G Tr? Cigale 

2] MMINERALY [SW.00 Listy ¢ 

as ‘i : A POLE PELE LIE y are LLLPPLIIILII EF iy, 

eM 17 mes a 2 Rr? 23 
wh = Lreserrorede, 4 


~eaerwarrrlilrarccrsradisrrraccrraly OTTO LL 


LF 
222) Lean 


Z 


~ 
ZZ) 









Fig. 204. 


or horizontal, to receive the grounds or wood finish. Three-inch 
hollow partition blocks are also sometimes used for furring. 


Fig. 204 shows a good method of furring the walls of rooms used 
for cold storage, etc. 


CHAPTER X. 


TRON AND STEEL SUPPORTS FOR MASON 
WORK.—SKELETON CONSTRUCTION. 


322. Although constructions of iron and steel do not properly come 
within the scope of this volume, there are so many places where 
metal work is used in connection with brick, stone and terra cotta 
that it has been thought desirable to briefly describe the most com- 
mon forms of iron and steel construction used for supporting masonry 
walls, and the various minor details of metal work used in connection 
with the mason work. ; 

Girders and Lintels.—All openings in masonry walls which it 
is not feasible to span with arches should have iron or steel lintels or 
girders to support the mason work above. The objections to wooden 
beams for supporting mason work are given in Section 255. 

Since the price of rolled steel has been so greatly reduced, girders 
and lintels for supporting brick and stone walls are almost univer- 
sally formed of steel I-beams, or girders built up of steel plates and 
angle bars. Except for very wide spans and exceptionally heavy 
loads, steel I-beams may be most economically used for such sup- 
ports. As a rule,at least two beams should be used to support a 
g-inch or 12-inch wall, and three beams for a 16-inch wall, the size of 
the beams, of course, depending upon the weight to be supported. The 
beams should be connected at their ends, and every 4 or 5 feet 
between with boits and cast iron separators, cast so as to exactly fit 
between the beams. The girders should have a bearing at each end 
of at least 6 inches, and should also rest on cast iron bearing plates 
of ample size. 

If the wall to be supported is of brick, the first course above the 
girder should be laid all headers. The width of the girder is gener- 
ally made 2 inches less than that of the wall. In calculating the 
weight to be supported by a girder, much depends upon the structure 
of the wall above. If the wall is without openings, and does not sup- 
port floor beams, only the portion of the wall included within the 


302 BUILIVNG CONSTR OCLIOIN, 


dotted lines, Fig. 205, need be considered as being supported by the 
girder. The beams in that case, however, should be made very stiff, 
so as to have little deflection. If there are several openings above the 
girder, and especially if there be a pier over the centre of the girder, 

















Fig. 205. 


as shown in Fig. 206, then the man- 
ner in which the weight bears on 
the girder should be carefully con- 
sidered.. Inacase such as is shown 
in Fig. 206 the entire dead weight 
included between the dotted lines 
A A and & SB should be consid- 
ered as coming on the girder, and 
proper allowance made for the load being mostly concentrated at the 
centre. 

Steel lintels for supporting stone or terra cotta caps and flat arches 
are described in Section rgo. 

323. Cast Iron Lintels.—Lintels of cast iron were at one time 
extensively used for supporting brick walls over store fronts and door 
openings, and even at the present time are used to some extent. On 
account of the brittle character of this metal, however, and its low 
tensile strength, it should not be used for beams subjected to a moving 
load, such as floors upon which heavy articles are moved. 

Cast iron beams of long span are also not as economical as those 
made of rolled steel. About the only places, therefore, in which cast 
iron lintels may be suitably and economically used, are over store 
fronts where the span does not exceed 8 feet, and over door openings 
in unfinished brick partitions where a flat head is necessary. The 





Fig. 206. 


IRON SUPPORTS FOR MASON WORK. 303 


relative economy between cast iron and steel lintels will depend 
largely upon the distance from the rolling mills and upon freight rates, 
Foundries for casting iron are much more widely distributed than 
rolling mills, so that castings of almost any shape can usually be 
obtained in any city of twenty thousand inhabitants, while mills for 
rolling steel beams are comparatively few in number and located 
mostly in the extreme eastern portion of the country. 

The common shape for cast lintels over door openings is that shown 





Fig. 207. Fig. 208. 


in Fig. 207. The width of the flange is usually made the full thick- 
ness of the wall, and the extreme height of the lintel at the centre 
not less than two-thirds nor greater than the width of the flange. The 
strength of the lintel may be somewhat increased by stiffening the 
web at the centre by brackets, as shown by dotted lines at A. 

Where the width of the flange must be over 16 inches two webs 
should be used, as shown by the section drawing, Fig. 208. For 
handling and moulding it is best not to make the flange more than 
24 inches wide; if a greater width than this is required, several lintels 





Fig. 209. 


should be placed side by side. The thickness of the metal should not 
be less than 2 inch, and the web should be about ¢ inch thicker than 
the flange. 


304 BOLLDING CON STIROG Cd IGNe 


When proportioned as above the strength of the liniel to support a 
dead load may be safely made equal to 


g700 X area of bottom flange X extreme depth 
span in inches. 








Fig. 210.—Store Front Lintel. 


Thus a lintel of 6 feet clear span with 12-inch by #-1nch flange and 
extreme depth of 12 inches should safely support 


MEL OS = 14,550 pounds. 

Lintels over store fronts should 
LJ be made with ribs at the ends, as 
shown in Fig. 209, with holes for 
bolting the lintels to each other 
and to columns. Store front lin- 
tels are also occasionally made as 
shown in Fig. 210, to give a finish 
above the openings. 

Fig. 211 shows details for cast 
iron lintel and sill, sometimes used 
for windows in external walls. The 
thickness of the metal need not 
exceed 3 of an inch. 

324. Cast Iron Arch Girders are also sometimes used to sup- 
port brick and stone walls where the opening is from ro to 30 feet 
in width. Fig. 212 shows a girder of this kind that was used to sup- 
port a central tower over the crossing of the nave and transept on 
St. John’s Church, Stockton, California, Mr. A. Page Brown, archi- 
tect. The clear span is 294 feet, and the height of the wall above 
the girder 18 feet. One object in using such a girder in this place 
was to get the neight in the centre without also raising the supports, 





Fig. 211. 


IRON SOPPORTS FOR MASON WORK. 305 


which could not be obtained with a steel plate girder. The church 
has a vaulted ceiling which comes just below the arch of the girder, 
the tie-rod being exposed. 





SectionatCe nter. 


Fig. 212. 


The rise of the casting in this case is rather more than common, 
the usual rise being from +4, totor the span. The end of the girder 
is generally cast in the shape of a hollow box, with shoulders to 
receive the ends of the rods. ‘The tie-rod is often made with square 
ends, and about $ inch shorter than the casting, and is heated until 
the expansion perraits of its being slipped into its place in the cast- 
ing. As it cools the contraction binds it tightly into its place. If 
tightened by means of a screw and nut, the nut and bearings should 
be dressed to a smooth surface and the rod turned up with a long- 
handled wrench. It is very essential 
that the rod shall be fitted in place so 
tightly that no tensile strain can come 
on the casting, and, on the other hand, 
it should not be expanded so as to 
bring an initial strain on the arch. 

This form of girder is comparatively 
little used now, but there may be con- 
ditions, as in the church mentioned 
above, where it can be used to advan- 
tage. 

325. Supports for Bay Win- 
dows.—Where bay windows having 
walls of brick, stone or terra cotta 
start above the first story, it is neces- 
sary to support them in some way by 
; metal work. 

If the bottom of the bay is of stone, and the projection is not more 
than 2 feet, the bay may be supported directly from the wall by cor- 





306 BUILDING CONSTRUCTION. 


beling out the stonework as shown in Fig. 213. The stone 4 should 
be the full size of the bay if possible, and should be bolted down by 
means of long rods built into the wall and secured to two channel 
bars (as in the figure) placed on top of the stone and with their 
ends built into the main wall. 





Fig. 214. 


If the bottom of the bay is of copper, and at a floor level, the sim- 
plest and strongest method of supporting the bay is that shown in 
Fig. 214. 

Steel I-beams are extended across the wall of the story below and 
framed to a pair of channels, bent to the shape of the bay. The 
I-beams should be carried far 


enough inside of the walls to give 4 354 ih ok gan 
them a sufficient anchorage to off- “oT i 
set the leverage of the outer end, ‘SectionatA -) 






MUM TETIAOIEITN EERIE 


and should be secured to a girder or Se 
eee 
WZ 


partition running parallel with the 
wall or to another steel beam at 
right angles with them, and form- 
- ing part of the floor construction. 
The channel bars forming the 
support for the walls of the bay . 
should also be built into the wal] 
on each side and anchored by iron 
rods built into the masonry below. 
Fig. 215 shows a method of supporting a light bay by cast iron 
brackets bolted to the wall, which has been used where the bottom 
of the bay was above the floor line. The bottom of the bay in this 


SABLE LUIVE CONSTRUCTION 307 


construction may be either of copper or terra cotta, the latter, if used, 
being suspended from the bracket by hook anchors. If such cons 
struction is used a steel channel should be bolted to the top of the 
wall and extended well into the side walls, to prevent the brackets 
from pulling away the brickwork. Examples of bay supports in skel- 
eton construction are also shown in Figs. 221 and 222. 


326. Wall Supports in Skeleton Construction.—In build- 
ings built on the skeleton plan, now so generally used for high office 
buildings, all the weight of the walls, including the masonry surround- 
ing the outer columns, is supported by the steel skeleton, at least above 
the third story. The outer walls of the lower stories, when of stone- 
work, are sometimes supported directly from the foundations, as was 
the case in the New York Life Building, Chicago.* 


When the walls are supported by the steel skeleton they are gener- 
ally made very thin—about 12 inches, and sometimes only g inches 
thick—and in the more recent buildings the wall is supported at every 
story, so that the wall in any story could be removed without affecting 
the wall above or below. 

The materials generally used for the outer walls are brick and terra 
cotta, these being preferred on account of the ease with which they 
may be handled and the facility with which they maybe built about 
and between the beams and columns. Brick and terra cotta also 
appear to be about the only suitable materials for the walls of a fire- 
proof building. 

It has been found very difficult to attach stonework to the metal 
frame, and this, together with the low fire-resisting qualities of most 
building stones, has practically prohibited the use of this material 
except in the lower stories. In the Reliance Building, Chicago, thin 
slabs of highly polished granite enclosed in ornamental metal frames 
were used for casing the columns in the first story. 

The general plan of the exterior walls in this class of buildings 
consists of vertical piers, from 3 to 4 feet wide, which inclose the 
exterior columns and extend from the bottom to the top of the build. 
ing. The space between these piers is generally nearly filled by the 
windows, either flat or in the form of bays, leaving only a small piece 
of wall, from 4 to 5 feet high, between the tops and bottoms of the 
windows to be supported by the frame. These portions of wall 
between the piers and the windows are called spandrels. 

The mason work of the piers is generally supported by angle 





* Jenney & Mundie, architects. 


308 BUILDING, CONST OCHO. 


brackets attached to the columns, and the spandrels are supported 
by steel beams or girders of various shapes, called spandrel beams. 
The spandrel beams extend from column to column, and are riveted 
to them. 


The arrangement of the metal work for supporting the spandrel 
walls will depend largely upon the architectural effect sought by the 
designer and upon the materials used, so that the details vary some- 
what in every building, and often in different portions of the same 
building. No general rule or form of construction can therefore be 
given for arranging such supports, but the architect must use such 
arrangements as seem best suited to the design of the building he has 
in hand. The following examples, however, will show how the walls 






SS BS Sor 
SY 


PSD IAA{4QV 
Ae 
NSS 







NY, 





|Lines C-G on center of Columns, 


Fig. 216. 


have been supported in several buildings, and with slight variations 
one or another of these methods can be adapted to almost any build- 
ing. 

It is probably hardly necessary to say that the metal work in this 
class of buildings should be very carefully designed and studied to 
suit the conditions of the building, and to provide ample strength, 
as well as arranged so that it may be fully protected from heat. Con- 
sideration must also be given to the effects of expansion and con- 
traction in the frame. 


327. Spandrel Supports.—The simplest case of spandrel sup- 
ports is where the wall is perfectly plain and built of brick, with 
terra cotta caps and sills. In such cases a channel and angle bar 
may be used to support the outer face of the wall and an I-beam the 


SALLESON CON STROCTION. 200 


backing, as shown in Fig. 216, which shows sections of the outer 
walls of the Champlain Building, Chicago.* 

The channel and I-beam should be bolted together with cast sep- 
arators made to fit. 

For a plain wall, channels and angles seem to be the best shape for 
the outer portion of the spandrel support, as they are of an economi- 
cal section, and, the flat face of the channel being outward, a 4-inch 
veneer of brick can be set in front of it without clipping the brick. 

The face of the chan- 

Y A nelis generally set 5 or 

6 inches from the face 
Gy. of the wall, and 3x3 






wy angles are used for 
Ug supporting the outer 
a Naniome et oches of wall) ‘The 
pS TERAA COTM. Outer edge of the an- 


gle should come within 
24 inches of the face 
of the wall. 

Spandrel supports 
very similar to those 
shown in Fig. 216 have 


| 
| 


. Ou One” 





been used in several 
Chicago buildings. 

Z-bars have also 
been used in several 
buildings in place of 
the channel and an- 
gle, but are not gener- 
ally considered quite 
as satisfactory, as they 
do not give the same 
strength for the weight 
of metal used. 

Fig. 217 shows a Z-bar support used for the attic wall of the Wyan- 
dotte Building, Columbus, Ohio.t 

Fig. 218, from the New York Life Building, Chicago, shows the 
spandrel supported by a single I-beam, the 4-inch facing of the wall 
being supported by the terra cotta lintel which is hung from the beam. 


SECTION THROUGH Arric 


Fig. 217. 





* Holabird & Roche, architects. 
+D.H. Burnham & Co , architects. 


310 BOLLDING- CON SLAOUC LION: 


In the Reliance Building™ plate girders were used for the main 
spandrel supports, and two angles riveted together to make a T were 
bracketed from the outer face of the girder to support the wall, the 
girder being on the centre line of the columns. 


Fig. 219 shows the method used for supporting the granite walls 
at the fourth floor level of the Masonic Temple, Chicago. It should 
be noticed that an open joint is left opposite the supporting angle to 
allow for expansion and contraction in the column. 


When the wall is faced with ornamental terra cotta the latter can 
seldom be supported directly by the spandrel beams, and a system of 
anchors must be resorted to, to 
properly tie the individual blocks 
either to the brick backing or to 
the metal work. ‘These anchors 
are usually made of 4-inch square 
or round iron rods, which are 
hooked into the ribs provided in 
the terra cotta blocks, and then 
Nh drawn tight to the brickwork or 

oc eo zt metal work by 
SG a PUNCH} HoLes 6'on Means Of nuts and 
CENTERS CORES Screw eels. 105 
shown in Fig. 221. 





Roane ~ Hook bolts are 
largely used for 
| CAST *mon Face tying “terra cotta 
blocks to the metal 

Fig) as8, work, the ends be- 


ing bent around the 
bottom of the beams, channels or angles. Several examples of the 
use of hook bolts are shown in Figs. 218, 220, 221 and 222. 


A great variety of methods for properly securing the terra cotta are 
possible. ‘They should be carefully studied and the general scheme 
should always be indicated on the spandrel sections, in the manner 
shown in the illustrations, as the holes in the structural metal work 
necessary to receive the anchors should be shown on the detail draw- 
ings of the iron and steel work, so that the punching may be done 
at the shop. The inexperienced architect should also consult with 


*D. H. Burnham & Co., architects. 


SKELETON CONSTRUCTION. 311 


the manufacturers cf the terra cotta work as to the best manner ot 
securing the blocks. 


The anchorage of the brick and terra cotta to the steel frame is a 
matter of vital importance, as very serious consequences are quite 
sure to follow any neglect in 
this matter: “An instance is 
known where a whole section of 
wall facing on the court side of 
-a high building fell off because 
the workmen omitted the an- 
chors.” As all the anchors for 

\s every block cannot be exactly 
i: NS y shown on the drawings, either 
Wy » Yj 7 the architect or some one in his 
V//, employ should give this portion 
WW Lee of the work the strictest super- 
iS intendence. 


Coe to 328. Bay Windows.— 
These have become a _ very 
prominent feature in the mod- 
ern office building and _ hotel. 
In skeleton buildings the mason 
work of the bays is made as 
light as possible, with slight 
terra cotta mullions and angles, 
and is supported in each story 
by brackets built out from the 
spendrel beams or girders, as 
shown in Figs. 221 and 222, 
which are sections from the 
- Wyandotte Building. 








Tor 





oF 4I# FLOOR 


— = T 





INSIDE LINE OF ARCH 
WR 


Le Seen 2 asqi.t ee) 


wg — e—— - 


As the leverage on_ these 
brackets is considerable, they 
should be securely riveted to the spandrel beam, and the latter well 
tied or framed to the floor construction to keep it from twisting. 


Fig. 219. 


Where mullions occur between windows, and at the angles of the 
bays, cast iron or steel angle or T-bars are bolted or riveted to the 
metal work above and below, to stay the frames and terra cotta mul- 
lions and angles, in the manner shown in Fig. 223. 

The importance of thoroughly fireproofing the exterior columns 


312 BUILDING CONSTRUCTION. 


has already been considered in Chapter IX. Fig. 223, however, is 
given as an example of the pier construction in Chicago buildings. 

Further illustrations of the manner of supporting the mason work 
in this class of buildings may be found in Architectural Engineering, 
by Joseph K. Freitag, C. E., and several numbers of the Lugzneering 
Record and the Brickbuilder. 


329. Miscellaneous Ironwork.—The following details of iron- 
work used in connection with brickwork and stonework should per- 


eit z 
ROcuUiJIATS A) i 





| 
| 






| : 
GHANNEL PUNE MEO tve 
@ POR TERRA Gorra _ 
4° ABovE 


GoTTom sis ; po ee net 
ips N a ° ! PLASTER 
Ze mii 
i 







oa 
earl 








LOT 








fe INIT 





° 


Fig. 220.—Section New York Life Building 


haps be mentioned here, as they have to be considered when design- 
ing the mason work. 

Bearing Plates —Wherever iron or wooden posts, columns or gird- 
ers rest on brickwork, a cast iron or stone bearing plate should be 
used to distribute the concentrated weight over a safe area of the 
mason work. Several failures in buildings have resulted from care- 
lessness in this particular. Rules for proportioning the size of bear- 
ing plates are given inthe Architects’ and Builders’ Pocket Book. 

Cast Iron Skewbacks for Brick Arches—Wherever segmental 
arches are used over doors or windows, without ample abutments, 


SKELETON CONSTRUCTION. ek 


cast iron skewbacks, connected by iron rods of proper size, should 
be used to take up the thrust of the arch, as shown in Fig. 224. 
Shutter Eyes.—All fireproof doors and shutters in brick or stone 
walls should have hinges made of 2x34-inch flat iron bars, welded 
around a 34-inch diameter pin working in a cast iron shutter eye 
built into the wall. For brick walls the shape shown at a, Fig. 225, 


= ty te 
— = 


Po SSyp 
‘ 
Z . 
| mer 
4 iG | 1 
SSS 
NJ - 


———2 


IN& OF COL 


a 
| 


BUILPING LINE 






Ny 

\) 
SSUES ENN / Woo 
LILLE Do ay TERRA COTTA , 


a K LL La LL YP 
EAN 


SESS oe ee 








TERRA COTTA 
ARCH 






PLASTER LINE 


neers aee Dae Fv enemas fo te i 


TT 
EZ es Se ice ol 


Fig. 221. 


. is about the best for the eyes, although for very heavy doors or shut- 
ters the strength of the face should be increased by having another 
web. For stone walls the shape shown at 6 should be used. The 
thickness of the metal is generally made 4 of an inch. 

Door Guards and Bumpers.—lit is a good idea to protect the brick 
jambs of the carriage doors in stables by bumpers, which are rounded 
projections on the corners extending 12 to 18 inches above the ground 


314 BOULLDING CONST ROCITON. 


and about 8 inches beyond the wall and jamb, so that if the carriage 
wheel strikes the bumper the hub will not scratch the brick jamb. 
Such bumpers may be made either of some hard stone or of iron. 












RAMs 
yA # ,; — —— 2, 
SLO Bry ey SNR IV G 
Sh Str ATi ON —— 2 














’) 
BY, 
| 






x 
ASSSSSSNS SSO 
MUOWOMUETTTMMGL My 
Z 


Fig. 222.—Section Through Top of Bays. 


‘ 
‘tad, ANCHORS TO EACH WINDOW BOX 


Fig. 223 —Plan of Piers and Mullions in Alley and Light Court, 
New York Life Building, Chicago. 


The jambs of the exterior doors to freight elevators and of the deliv- 
ery and receiving doorways in mercantile buildings should also be 
protected for a height of 4 or 5 feet above the sill by iron guards, to 


SKELETON CONSTRUCTION. 315 


prevent the brickwork being broken by boxes, trucks, etc. Such 
guards are generally made of cast iron about 4 inch thick, as castings 
can more easily be fastened to the wall than plate iron. The 





Fig. 224. Fig. 225. 


castings, or plates, should be made with lugs on the inside pierced 
with holes for clamping them securely to the brickwork as the wall is 
built. Fig. 226 shows a section of one of the alley piers of the New 


‘IRON WHEEL GUARD 






























He al 


[anTjess fos} 










Fig 226. 


York Life Building, Chicago, and the manner in which the iron 
guards are attached to the brickwork. A similar arrangement can be 
adapted to any door jamb. In Chicago it is quite common to protect 


316 BULELDING - CONSLAOGCLION: 


Fig. 227. 





Fig 228. 


the bottoms of the piers on the alleys in this way to prevent injury to 

the walls from passing teams. 

erally considered the most durable finish for the top. The usual 

shape of such caps is 

that shown in Fig. 227. 

and prevents the bricks 

j in the upper courses 

from becoming loose. 

beled out as shown the 

cap also acts as a drip to protect the sides of the chimney, at least 

near the top. The inner lip ot the cap should extend down into the 

square it need be but } of an inch thick; if larger than this the 
thickness should be increased to # inch. 

If the cap is 3 feet square or greater, for convenience in handling 
four sections, which should be bolted 
together, flanges being cast on the under 

side for this purpose. 

desirable to have a ladder built inside 
of large brick flues, or shafts, and on the 
outside of tall chimneys to serve as a 
ladders are usually made of ?-inch round 
iron bars, bent to the shape shown in 
Fig. 228 and placed in the wall of the 
climbing the rungs should be placed 12 
inches apart between centres, and should 
be about 18 inches wide and project 6 

Coal Hole Covers and Frames.—When coal vaults are placed under 

the sidewalk the architect should specify iron frames and covers for 

the holes made for putting in the coal. If the vault is covered with 


330. Chimney Caps.—For tall chimneys a cast iron cap is gen- 
ae ee ae y] rm Such a cap completely 
Cc / Y ] { protects the mortar 
i) Ea 
] / ys joints from the weather 
Do 
és ip ; 

If the chimney 1s cor- 
chimney from 8 to 12 inches. If the cap is not larger than 4 feet 
and casting it should be made in two or 

Chimney Ladders—It is sometimes 
ready means of reaching the top. Such 
chimney, or flue, when built. For easy 
inches from the wall. 
granite flagging a rebate may be cut in the stone to receive the cover, 


SKELETON CONSTRUCTION. 317 


and no frame is necessary. In all other stones, and in cement walks, 
the hole should be protected by a cast iron frame at least 4 inches 
deep. The frame is generally cast with a projecting ring about 2 
inches wide and $# inch thick, which should set in a rebate cut in the 
stone and filled with soft Portland cement. The frame is also made 
with a #-inch rebate for the iron cover. The cover is made of cast 
iron about: 4 inch thick and should have a roughened surface 
on top. ‘The covers are sometimes made with holes, into which glass 
bull’s eyes are cemented to admit light to the vault. Both solid and 
glazed covers are generally carried in stock by the larger iron foun- 
dries, and in sizes from 16 to 24 inches in diameter. 


CHAPTER XI. 


CATHIN GAAN DEE IAS TERING. 


—— 


331. Probably 99 per cent. of modern buildings, in this country 
at least, have plastered walls, ceilings and partitions. It is only lately, 
however, that much attention has been given to this branch of build: 
ing operations, and there is probably no doubt but that much of the 
plastering done at the present day is inferior to that done fifty or one 
- hundred years ago. | 

The introduction of fireproof construction and the desirability of 
completing large and costly business buildings in the shortest pos- 
sible time has shown the necessity for improvements in the materials 
used both for the lathing and the plastering, and several new mate- 
rials have been introduced to meet the demand. 

Even in dwellings it is important that the finish of the walls and 
ceilings shall be as nearly perfect as possible, as large sums of money 
are not infrequently spent on their decoration, and it is therefore 
essential that the ground work shall be so durable that the decora- 
tions will not be ruined by broken walls or falling ceilings. The 
quality of the workmanship is also of much importance, as nothing 
mars the appearance of a room more than crooked walls and angles, 
and dents, cracks and patches in the plastering. 

To secure a good job of lathing and plastering it is essential that 
only the best materials be specified and used, and that the mortar be 
properly prepared and applied. Thesé can only be insured by being 
careful to specify exactly how the work shall be done and the mate- 
rials that shall be used, and supplementing the specifications by effi- 
cient supervision. In order to furnish such specifications and super- 
intendence, it is obviously necessary that the architect.shall be thor- 
oughly familiar with the materials used and the way in which they 


should be applied. 
LATHING. 


332. Brick walls and hollow tile ceilings and partititions do not 
require lathing, as the plastering may be applied to them directly, the 
brick and tiles having an affinity for the mortar which holds it 


LATHING AND PLASTERING. 319 


securely in place. All other constructions require some form of 
lathing to serve as a ground to receive and hold the plaster. 

Wooden Laths.—Practically all dwellings of moderate cost, 
and a large proportion of other buildings, are still lathed with wooden 
laths, and if of good quality they give very satisfactory results where 
no fireproof ‘quality is expected. It is generally admitted that the 
best wood for laths is white pine, although nearly as many are made 
of spruce, which answers very well. Hard pine is not a good mate- 
rial for laths, as it contains too much pitch. 

Wooden laths should be well seasoned and free from sap, bark and 
dead knots. Small sound knots are not particularly objectionable. 
Bark is often found on the edges of laths, and is probably the great- 
est defect that they are subject to, as it is quite sure 
= /] to stain through the plaster. | 
The usual dimensions of wooden laths are 4% x1\% 
3/| inches in section and 4 feet long; the width and thick- 
ness vary somewhat in different mills, but the length 
is always the same. The studding or furring strips 
should therefore be spaced either 12 or 16 inches apart 
from centres; 12-inch spacing gives five nailings to the 
| Jath, and 16-inch spacing four nailings. 

The former obviously makes the stronger and better 

Se es wall. It is particularly desirable that laths on ceilings 
have five nailings, as there is more strain on them than on those on 
the walls. 

Sheathing Lath.—A combination sheathing and lath, known as the 
Byrkit-Hall Sheathing Lath, has been on the market for 15 years, 
and is highly endorsed by Architects for the purposes intended. It 
is made by special machinery from pine, hemlock, cypress, and pop- 
lar, in same lengths as flooring and in 4 and 6 inch widths, the edges 
being both tongued and grooved and square. The general principle 
of the lath is shown by Fig. 229, a full-size section and more com- 
plete description being given in section 143 of Part II. 

When used on the outside of frame walls, it answers the purpose of 
sheathing, and also forms a clinch for back plastering on the inside. 

For Stucco buildings, staff, plaster of paris ornamentations, and 
imitations of stone, the grooved side can be placed out to receive 
the mortar. 

Thirty million feet of this lath were used on the Columbian Expo- 
sition Buildings in 1892 and 1893; Twelve million feet on the Pan 
American Exposition Buildings and about thirty million feet will be 





320 BUILDING CONSTRUCTION. 


used at St. Louis, Missouri Over eighty five million feet of the 
Byrkit Lath are now used annually in the United States. In the 
North, Northwest and middle States, this lath has been extensively 
used for rough cast, back plastering and interior lathing. 

333. Metal Laths.— Wire Cloth.—About eighteen years ago | 
when the interest in fireproof construction became more general, 
wire netting came into use as a substitute for the wood lath. It was 
found that the strands of the netting became completely imbedded in 
the plaster and held it so securely that it could not become detached 
by any ordinary accidents. The plaster also protects the wire from 
the heat, and the body of: the metal is so small that there is no 
appreciable expansion of the metal when subjected to fire. 

The author believes that heavy wire cloth tightly stretched over 
metal furrings forms the most fireproof lath now on the market, and 
he has personally seen it demonstrated by severe experimental tests, 
and by actual fires in buildings, that plaster on wire cloth, and par- 
ticularly hard plasters, will protect the woodwork from a severe fire 
so long as the plaster remains intact, provzded there are no cracks or 
loopholes at the corners and around columns where the fire can get 
through. 

The objection has been found to the ordinary wire lath that it is diffi- 
cult to stretch it so tight that it will not yield to the pressure ‘exerted 
in applying the several coats. Another objection that is made to the 
wire lath, and also to the expanded lath (Fig. 231), is that they take 
a great deal of plaster. From the standpoint of jrst cost this is 
undoubtedly a valid objection, but from a fireproof standpoint the 
great amount of mortar used is its principal value. It should be 
remembered that the mortar is the fireproof part of the wall or ceil- 
ing, and wof the metal. No metallic lath, the author believes, should 
be considered as fireproof which does not, in use, become imbedded tn 
the mortar, for if the thin coating of plaster peels off the metal lath 
will resist the fire no better than the wood lath, and will be more in 
the way of the fireman. | 

Wire lathing is now made in great variety to meet the requirements 
of the different plastering compositions and the varying conditions of 
construction. 

Plain lathing is plain* wire cloth, usually 24x24 meshes to the inch, 
made from No. 17 to No. 20 wire. No. 20 is more generally used 
' than any other size. 





_* The word plain is here used to designate ordinary wire cloth, without corrugations or stiff- 
ening bars. As used by the trade the word “plain”? means lathing that is not painted or 
galvanized. 


LATHING AND PLASTERING. 321 


The lathing is also sold plain, painted and galvanized. Painted o1 
galvanized lathing should be used in connection with special hard 
plaster compounds. Painted lathing costs about one cent per square 
yard more than “bright” lathing. 

Galvanizing the wire cloth after it is woven adds very much to its 
stiffness, as the zinc solders the wires together where they cross. 
Galvanized lathing is also less lable to corrosion before the plaster- 
ing is applied than the plain lathing. 

The usual widths of wire lathing are 32 and 36 inches, although 
the Roebling lath may be obtained of any width up to 8 feet. 

All wire lathing should be stretched tight when applied, so as to 
insure a firm surface for plastering. For this purpose stretchers are 
supplied by the manufacturers. 

Furring for Wire Lath.—\n order to properly protect wooden con- 
struction, such as beams, posts, studding or plank, from fire, by wire 
lath and plaster, it is essential that the lath be kept at least 3 inch away 
from the woodwork by iron furring of some form, and a 1-inch space is 
much better. This setting off of the lath from the wood is generally 
done either by means of bars woven into or attached to the lathing, 
or by means of iron furring put up before the lathing. Probably the 
most common method of furring with iron for wire lath has been by 
means of band iron, either straight or corrugated, $ inch or # inch 
wide, set on edge and secured to the under side of the joist or plank 
by narrow staples, driven so as to keep the iron in a vertical position. 

On floor beams and studding, unless heavy iron is used, it 1s nec- 
essary to run the furring lengthways of the beams and studding, and, 
as the latter are seldom less than 12 inches on centres, this does not 
give close enough bearings to secure a stiff surface for the plastering. 

Under plank (mill) floors the band iron should be spaced every 8 
inches, and, if corrugated iron is used, a very satisfactory surface is 
obtained. After the furring is fixed in place the cloth is then 
stretched over it and secured by staples nailed over the wire and the 
band iron. 

Hammond's Metal Furring=—A much better system of furring, and, 
so far as the author is informed, the most perfect of all systems of sefa- 
rate furring over woodwork, is that known as the “Hammond” furring, 
and shown by Fig. 230. It consists of a combination of sheet metal 
bearings and steel rods. The rods form the furring for keeping the 
wire cloth away from the timber, and the bearings form the offset for 
the rods, both being secured to the joist, studding or plank by means 
of staples, as shown in the figure. The rods, being only about } inch 


_ * Controlled by the Gilbert & Bennett Manufacturing Co. 


322 BUILDING CONSTRUCTION. 


in diameter, become completely imbedded in the plaster when it is 
applied, and as the plaster hardens it unites the rod and cloth so as 
tc make a much more rigid surface than is possible where band iron 
furring is used. The rods also may, and in fact should be, run across 
the beams or studding, and may therefore be spaced as close together 
as desired. It is recommended that the spacing of the rods be made 
74 inches where the joist are 12 inches on centres and 6 inches when 
the joist are 16 inches on centres (being 5 and 6 bars to each strip of 
lathing). The bearings are $ inch and 1 inch deep, the latter being 
recommended, as they give a greater air space between the plaster and 
timber, which is especially desirable in lathing around solid timbers 
or under planking. The 
rods come in lengths of 
about to feet. 

This system of furring is 
applicable to wooden posts, 
partitions and any form of 
wood construction; it 1s 
readily put up, and is but 
little more expensive than 
band iron. After the fur- 
ring 1s in place the wire 
cloth (which should be 
No. zo gauge, and painted 
or galvanized if hard plas- 
ters are to be used) is 
stretched over it, prefer- 
ably in the same direction as the rods, and secured by staples driven 
over the wire and one side of the bearing, as shown in the figure. 

Corrugated Wire Lathing.—A l\athing made of flat sheets of double 
twist warp lath, with corrugations 2 of an inch deep running length- 
wise of the sheet at intervals of 6 inches, has been used to some 
extent. The sheets are made 8x3 feet in size and applied directly to 
the under side of the floor timbers, to partitions or to brick walls, and 
fastened with staples. The corrugations afford space for the mortar 
to clinch behind the lath, and thus do away with the necessity for 
furring strips ; they also strengthen the lathing. 

Stiffened Wire Lathing.—In order to avoid the labor and expense 
of furring with metal, wire lathing having the furring strips attached 
to the fabric was introduced some years ago, and has been very 
extensively used, and the author would recommend that whenever 






































Wy WWWYWWYRAM 


























































































































Beets NG ANGI LAS. BLING. a23 


wire lathing is used over wood construction that either one of the 
stiffened wire laths, or ordinary wire cloth with the Hammond furring, 
be specified. 

Two varieties of stiffened wire lathing are now on the market. 
Each has been extensively used, with satisfactory results. 

The Clinton stiffened lath has corrugated steel furring strips 
attached every 8 inches crosswise of the fabric by means of metal 
clips. These strips constitute the furring, and the lath is applied 
directly to the under side of the floor joist, or to planking, furring, 
brick walls, etc. This lath is made in 32-inch and 36-inch widths 
and comes in 1oo-yard rolls. ; 

The Roebling stiffened lathing, made by the New Jersey Wire 
Cloth Co., is made of plain wire cloth, in which, at intervals of 74 

inches, stiffening ribs are woven. These 




















































See ribs have a V-shaped section and are 
oe =z si made of No. 24 sheet iron, and vary 
N\ \ 0 Pty | ° . 
oe Peete «= from «3 to 1% inches in depth. The 
PS Cocco lg ue! : 
i EERE y =-inch rib 1s the standard size for lathing 
am os 
SRemmic| on woodwork. This lathing requires no 
Coch furring, and is applied directly to wood- 
eee «= work or walls with steel nails driven 








Ton 
Ce 
i 


) through the bottom of the V, as shown 
(heb IDeOr., 

The No. 20 V-rib stiffened lathing 
affords a satisfactory surface for plas- 
tering, when attached to studs or beams spaced 16 inches apart. 
The lathing should be applied so that the widths will join on a beam 
or stud. 

The 14-inch V-rib lathing is used for furring exterior walls. It 
provides an air space between the wall and plaster. 

For iron construction a }-inch solid steel rod is substituted for the 
V-rib, and the lathing is attached to light iron furring with lacing wire. 

The Roebling lath is made with 2$x24, 3x3 and 3x5 mesh, the 
latter being known as “‘close-warp.” The 2$x2$} mesh should be 
used for ordinary lime and hair mortar, and the 3x3 or 3x5 mesh 
for hard plasters and thin partitions. ‘This lathing is also sold bright, 
painted and galvanized. 

The No. 20 painted wire has been extensively used, and much of 
it has been in service for from 6 to 8 years and is now apparently as 
good and strong as ever, so that there appears to be no necessity in 
ordinary work of using heavier wire or galvanized netting. 





| a 
a 
fey 


324 BUILDING CONSTRUCTION. 


The galvanized wire is stiffer than the painted, and would possibly 
wear longer, but it is doubtful if the advantages are at all propor- 
tionate with the cost. 


334. Expanded Metal Lath.—This lath (Fig. 231), now prob- 
ably well known to architects, is made from strips of thin, soft and 
_ tough steel by a mechanical process which pushes out or expands 
the metal into oblong meshes, and at the same time reverses the 
direction of the edge, so that the flat surface of the cut strand is at 
right angles with the general surface of the sheet. _ 


Two sizes of meshes are made, 38x14 inches and }x1} inches, the 
former being best adapted for the hard mortars and the latter for 
lime mortar. Both kinds are made in sheets 8 feet long and from 14 
to 20 inches in width, 18 inches being the standard widtk. 

This lath being flat and of 
considerable stiffness does not 
require to be stretched, and can 
be fastened directly to the under 
side of floor joist or to wood 
studding. If used on plank it 
should be fastened over metal 
furring strips. When applied 
to studding the lath should be 
placed so that the long way of 
the mesh will be at right angles 
to the studding, as shown in 
Fig. 231, as this insures the 
greatest rigidity. The studding 
or furring strips should be spaced 12 inches on centres and the lath- 
ing secured with staples 1 inch long, driven about 5 inches apart on 
the stud or joist. The lath, when applied, is a scant + inch thick, 
and to obtain a good wall $-inch grounds should be used. 




























































































There are several companies manufacturing this lathing under ter- 
ritorial rights, and it has been extensively used with very satisfactory 
results. The author believes it to be the most fireproof lath made 
from sheet metal. 


335. Perforated Sheet Metal Laths.—There are some six 
or more styles of metal lath made from sheet iron or,.steel by perforat- 
ing the sheets so as to give a clinch to the mortar. The sheets are 
generally corrugated or ribbed, also, in order to stiffen them and keep 
them away from the wood. There is not a great difference between 


LATHING AND PLASTERING. 325 


these laths, although some styles may possess certain advantages over 
the others. 

In general, the author would prefer those styles which have the 
greatest amount of perforations, or which approach the nearest to the 
expanded lath. All of these laths come in flat sheets about 8 feet 
ions and 15 to 24 inches in width, and are readily applied to wood- 
work by means of barbed wire nails. The nails should be driven 
every 3 Inches in each bearing, commencing at the centre of the sheet 
and working toward the ends. ‘These lath work very nicely in form- 
ing round corners and coves, and are generally preferred to the wire 
lath by plasterers, as they are easier to put on. They are certainly 
much superior to wood laths. Metal lath should never be cut at the 
angles of aroom, but bent to the shape of the angle and continued 
to the next stud beyond. This 
strengthens the wall and pre- 








vents cracks at the angles. 

Of the various forms of 
sheet metal lath in common use, 
the Bostwick lath (Fig. 231 A) 
is perhaps the best known 
and most extensively used. 
It is made of sheet steel, with 
ribs every # of an inch in the 
width of the sheet, and loops, 
3x13 inches, punched out between the ribs; the lath should be 
applied with the loop side out. This lath can be put on as fast as 
the wood lath, and is especially well adapted to round corners and 
coves. 

Picture mouldings should always be placed around all rooms lathed 
with metal lath, although screws can be quite readily secured in the 
lath by first making a small hole with a punch or drill. 

When using common lime mortar on metal lath the first coat should 
be gauged with plaster of Paris. Either painted, galvanized or 
japanned lath should always be used for hard plasters made by a 
chemical process, such as King’s Windsor and adamant. 

Aside from their fireproof qualities, wire or metal laths possess the 
advantages that plastering applied to them will not crack from 
shrinkage in the woodwork, nor can the plaster fall off. IZf the lath- 
ing is set away from the wood studding, the location of the timbers 
will not be shown by the plaster, as is invariably the case after a few 
years when wood laths are used. Metal laths are also proof against 














326 BOLLDING CON SLR GCLLOW, 


rats and mice, which makes them especially desirable in certain kinds 
of store buildings. Nearly all these advantages are lost when unstiff- 
ened wire cloth is stretched over wood furrings. 

336. Plaster Boards.—Thin boards made of plaster, and reeds 
or fibre, have also been quite extensively used, not exactly as a lath, 
but as a ground for the second and third coats of plaster. They are 
made in slabs about 2 inch thick, 16 inches wide and 4 feet long. 
The Mackite boards are made # inch and 1 inch thick for ordi- 
nary work. The under surface of the boards should be grooved or 
left rough to receive the plastering. 

The materials of which the boards are made consist chiefly of plas- 
ter of Paris and some sort of fibre. The Mackite boards also have 
hollow reeds imbedded in them. The boards can be sawed into any 
size or shape and nailed directly to the under side of the joist, or to 
studding or furring. ‘They are rapidly put on and require no scratch 
coat, and with some styles of boards a white or finished coat 1s all 
that is necessary. 

Actual fire tests appear to show that fire does not harm the plaster 
board more than the terra cotta tile, and on account of their light- 
ness, and the ease with which they can be cut, they are sometimes pre- 
ferred to tile or terra cotta for suspended ceilings under iron beams. 

Owing to the saving of plaster, the low cost of the boards and the 
ease with which they are put up, plaster boards probably offer the 
cheapest fireproof ceiling yet devised. 

In using plaster boards, or any of the patented laths, the architect 
or builder should follow the directions of the manufacturers as to the 
manner of putting up, etc., as there are often important precautions 
which might otherwise be overlooked. 

337. Where Metal Lathing Should be Used.—It is of 
course desirable that metal lathing or plaster boards should be used 
wherever any lathing is required, but the increased expense gener- 
ally prevents their use in the majority of buildings. 

There are, however, many places where it is particularly desirable, 
especially in buildings having ordinary wood floors and partitions. 
Such places are the under side of stairs in public buildings, the ceil- 
ings in audience and assembly rooms, under side of galleries, ceilings 
of boiler and furnace rooms, etc. ; 

Metal lathing should also be used on wood partitions, on both 
sides of hot air pipes. Where there are slots in brick walls for 
plumbing, hot air or steam pipes, they should be covered with metal 
lath, unless the walls are furred or the recesses cased with boards. 


LATHING AND PLASTERING. 327 


Metal lath should also be used at the junction of wood partitions 
and brick walls, when the walls are not furred, and particularly when 
the partition is parallel and flush with the wall. 

By using a strip of wire cloth or expanded metal, lapped 12 inches 
on the wall and partition, a crack at the juncture of the two will be 
avoided, and at only a very slight additional expense. 

It very often happens in outside brick walls that the arched wooden 
lintels over the windows come partly above the casing, and if the wall 
is plastered directly onto the brick the plastering generally cracks 
over, or will not stick to the lintel. This can be avoided by cover- 
ing the lintel with a strip of metal lath, lapped 6 or more inches on 
the brickwork. 

In general, wherever solid: timber has to be plastered, without 
room for furring and lathing, it should be covered with metal lath, 
which should also be lapped well on to the adjoining partition or wall. 


PLASTERING. 


338. Interior Work.—The very general practice of plastering 
walls and ceilings dates back not much more than a century ago. 
Previous to that time the walls and ceilings were either wainscoted, 
boarded, or covereé with canvas or tapestries, or else left rough. 

On account of its cheapness, its fireproof and deafening qualities, 
and its adaptability to decorative treatment, some kind of plastering 
will probably always be used for finishing the interior walls and ceil- 
ings of buildings. 

In describing plastering operations, it will be more convenient to 
divide the subject under the heads of Lime Plaster, Hard or Cement 
Plaster, Stucco Work and Exterior Plastering. 

Lime Plaster.—Materials.—Lime.— Until within about ten years 
all interior piastering used in this country was made of quicklime, 
sand and hair. 

There can be no question but that plaster made of a good quality of 
lime, thoroughly slaked and mixed in the proper manner, is very dur- 
_ able and also a valuable sanitary agent. Most of the lime plaster used 
~ at the present day, however, is very poorly and cheaply made, often 
of poor materials, and very much of it is far from durable. 

The stones from which lime is made, and the method of preparing 
it for the market, are described in Sections too and 154. 

Materials for making lime are found in nearly every State in the 
Union, but as no two quarries of stone are exactly alike, there is a 


328 BUILDING CONSTRUCTION. 


great difference in the quality of limes from different stones. In some 
localities, also, lime is obtained from shells and marble. 

The manner of working the lime also varies in different localities. 

In New England and New York lime is generally put up in casks 
or barrels and sold by measure, but in many of the Western States it 
is sold loose, like coal, and by weight. 

There are some limes which, while good enough for making ordi- 
nary mortar, are not suitable for making plaster; this is because all 
the particles of the lime do not immediately slake. Some of the par- 
ticles, because they are over-burned or for some other reason, will 
not slake with the bulk of the lime, but continue to absorb moisture, 
and finally after a long period, extending sometimes over two years, 
they will slake or “pop” and cause a speck of plaster to fall off. 

The author has seen walls and ceilings that were pitted all over 
from this cause. 

It is therefore important that the architect, when building in a new 
locality, or upon commencing his practice, should make inquiries as 
to the slaking qualities of the lime at hand, and where more than one 
lime is available, which one is the best. In some localities four or 
five different qualities of lime, from as many different places, are 
found on the market, and in such cases the architect should be very 
careful to specify the particular lime which he considers best. 
[Limes are generally known by the name of the locality where they 
are quarried.|_ Even in the best limes some particles do not slake 
quite as quickly as others, and it is not generally safe to apply any 
plastering in which the lime has not been slaked from ten days to two 
weeks. 

Sand, for plastering, should be angular, not too coarse nor too fine, 
and free from dust and all foreign substances. Methods of testing 
sand for foreign substances were described in Section 103. 

To make the very best plaster, the sand should be screened, washed 
and dried; sand prepared in this way can sometimes be obtained in 
the larger cities, but in most work the sand is merely screened. 

Of unprepared sand, river sand is generally the best, as it is less 
likely to contain impurities. Pit sand is very apt to contain clay. 

Sea sand is less angular than other sdnds, and is also considered 
objectionable on account of the salt contained init. It should never 
be used without thorough washing in fresh water. All sands require 
careful screening to take out the coarse particles, and sand for hard 
finish should be passed through a sieve. | 

Although the use of sand in mortar is principally to prevent shrink- 


LALTHING AND PLASTERING. 320 


ing and reduce the quantity of lime, it is also considered to have a 
valuable chemical function, causing the formation of a hard silicate. 
of lime, which pervades and strengthens the plaster. 

fair and Fibre.—To make the coarse plaster hang together better, 
hair or fibre should be mixed with the mortar for the ground work. 

Outside of a few of the large Eastern cities hair is almost entirely 
used for this purpose. For several years Manilla fibre, chopped 
about 2 inches long, has been used instead of hair for ordinary mor- 
tarin New York City and vicinity. Most of the patent mortars contain 
either asbestos or Manilla fibre. Fibre is cleaner than hair, and is 
said to be less injured by the lime. 

Most of the hair used by plasterers is taken from the hides of cat- 
tle, and is washed and dried and put up in paper bags, each bag 
being supposed to contain one bushel of hair after it is beat up. 

The weight is generally given as 7 or 8 pounds, but it often falls 
much short of this. 

If obtained from a local tannery, the hair should be thoroughly 
washed and separated before using. 

Hair is generally described in the specifications as “best quality 
of clean, long cattle hair,” but the plaster must take it as it comes in 
the bags. 

Goat hair is used to some extent in the Eastern States. It is 
longer and of a better quality than cattle hair. 

339. Mixing Mortar for Plastering.—The proper mixing of 
lime mortar is nearly as important as the quality of the lime. The 
tendency to reduce the cost of building to the lowest possible point, 
and to shorten the time required for the various operations, has, with 
other influences, led to much neglect in the mixing of mortar, and it 
is safe to say that three-quarters of the lime plaster used at the pres- 
ent time is not properly mixed. 

Where mortar is mixed by hand at the site of the building, the fol- 
lowing method is probably the best that can be considered as 
practicable : 

First the lime should be thoroughly slaked in a tight box, or, if the 
lime is not pure, so that a residue is left after slaking, it should be 
run off through a wire sieve into another box and allowed to stand 
for from twenty-four hours to seven days. 

Second. After the lime has been slaked the required length of time 
the hair should be beat up and thoroughly incorporated with the lime 
paste with a hoe, and the proper amount of sand then added and the 
mixture thrown into a pile. 


330 BOULILDINGICON S LRU LON: 


Third. After the mortar has stood in the pile not less than seven 
days, it should be wet up with water to the proper consistency in 
small quantities and immediately applied to the lathing or brickwork. 

The ordinary method of mixing plastering mortar is to mix the hair 
and sand with the lime as soon as it is slaked, and then throw the 
mortar into a pile, the whole process occupying but one or two hours. 
The objection to this method is that the lime does not always get 
thoroughly slaked, and the hot lime and the steam caused by the 
slaking burn or rot the hair so as almost to destroy its function of 
strengthening the plaster. For all good work the architect should 
specify that the lime be slaked at least twenty-four hours before 
working in the hair. 

For U. S. Government work the hair is not mixed in until the mor- 
tar is wet up for putting on, which is still better, but rather more 
expensive. 

If the mortar is required in freezing weather it should be made 
under cover, and under no circumstances should the architect permit 
the use of mortar that ha; been frozen. . 


The mixing of mortar in basements, although sometimes found 
necessary, is not desirable, as it introduces much moisture into the 
building. Mortar should never be made in the building when practi- 
cable to avoid it. 


340. Machine-made Mortar.—In New York City, Philadel- 
phia, and possibly some other places, mortar, both for bricklaying and 
plastering, is now made by machinery in buildings specially arranged 
for the purpose, and delivered at the work in cart load lots in a wet 
and plastic condition, with the hair or fibre, and fresh water incor- 
porated with the lime and sand, ready for use, without the addition 
of any other material or further manipulation whatever. 


The advantages of having the mortar made in this way are that 
ample time is given the lime to slake, the hair and sand are not mixed 
with the lime until just before delivery, and the mixing is much more 
thoroughly and evenly done by machinery than is possible by hand. 


Using mortar mixed at some other place than in the building per- 
mits of finishing the lower stories sooner than could otherwise be 
done, and also does away with the inconvenience of having a large 
pile of mortar stacked on the sidewalk or in the basement. 


Machine-made mortar was used in the Corn Exchange, the Man- 


hattan Life Building, the Home Life Insurance Building, and many 
other large buildings in New York. 


LATHING AND PLASTERING. 331 


The process of making the mortar in the Philadelphia plant is 
described as follows: 


Into four slacking machines or revolving pans, about twelve bushels of lime are 
placed and enough water introduced to slack without burning. The pan is started 
and the lime is kept in motion by a mechanical arrangement consisting of three feet 
on a perpendicular shaft. When the slacking is complete a plug is removed, and 
the lime and water carried by a trough through three screens into a well; from this 
well it is pumped into vats located in the upper floors of the mixing house. Screen- 
ing the lime eliminates all core or underburnt limestone, stones and other foreign 
matter so injurious to mortar, especially that used by plasterers. 

When the lime and water is pumped into the vats it much resembles thick milk, 
which, after standing three weeks, assumes the consistency of soft cheese. Water is 
allowed to stand in these vats, which further aids in the slacking of any minute par- 
ticles that have escaped through the sieves, and also to prevent the air from reaching 
it. (The lime used contains a considerable amount of magnesia, a pure carbonate 
not giving the setting qualities desirable.) 

When mortar is to be made this lime paste is carried to the mixing pans, which 
are like those used in slacking, with the exception that they have two sets of feet; 
sharp, clean bar sand is also placed in the pans, and the machine thoroughly incor- 
porates the lime and sand into a homogeneous mass, not a streak of lime and a streak 
of sand, but a material of uniform evenness. As a result of this care, I have tested 
brickquetts made of machine mortar and have obtained as great a tensile strain as 52 
pounds to the square inch ; in twenty-seven or twenty-eight days, out of three brick- 
quetts broken, I secured 48, 52 and 50 pounds tensile strain. We never allow lime 
to air slack ; neither do we mix the sand with the hot lime and allow it to stand.* 


When mixing mortar by hand, the nearer the process approaches 
the above the better will be the quality of the plastering. 

341. Proportion of Materials.—It has been found by repeated 
experiments that a barrel of Rockland lump lime, thoroughly slaked, 
will yield on an average 2.72 barrels of lime paste. Some limes will 
yield more and others less, the average of four Eastern limes tested 
being 2.62 barrels of paste. It has also been demonstrated by 
repeated experiments that the average-sum of voids in sharp, clean, 
silicious bank or pit sand, taken from different locations and ‘thor- 
oughly screened, is .349 of its bulk. It was also shown that the dest 
mortar is obtained by mixing with the sand such an amount of lime 
paste as will be from 45 to 50 per cent. greater than the amount 
needed to fill the voids of the sand, which practically requires a pro- 
portion of 1 part lime paste to 2 of sand. This is the proportion 
usually specified on Government work. 

As it is difficult to measure the lime paste, it would perhaps be 
better to specify that only 5} barrels of screened sand should be used 





* Henry Longcope, in the Brickburlder. 


332 BOULILDING CONSTRUCTION. 


to one cask of lime. Where lime is sold by weight about the same 
proportions will be obtained by specifying 2$ barrels of sand to 100 
pounds of dry lime. 

Mixed in the above proportions it will require about 2} casks, or 
500 pounds, of lime and 14 barrels (42 cubic feet) of sand to cover 
tco yards of lath work, }# inch thick over the lath. 


The proportion of hair to lime should be for first-class work, 1 
bushels of hair to one cask, or 200 pounds, of lime for the scratch 
coat, and 4 bushel of hair to one cask of lime for the brown coat. 
This is considerably more, however, than will be found in most 
plaster. 

The proportion of lime given above is none too rich for first-class 
plaster, either for the brown or scratch coat, but it is seldom, if ever, 
that brown mortar is made as rich as this, and much first-coat work 
is inferior to it. 

In fact, it is almost impossible to regulate the proportion and uni- 
for n mixing of common plaster. Where lime is sold by the cask it 
can be done by mixing one cask of lime at a time and measuring the 
sand, but where lime is sold by weight it would be necessary to keep 
scales on the ground for weighing the lime; and in either case it 
would be necessary to have an inspector to watch the making of the 
mortar. 

In practice the lime is slaked and as much sand mixed with it as 
the mortar mixer thinks best or the plaster will stand, and it is almost 
impossible for the architect to tell whether or not there is too much» 
sand. It seldom happens that there is too little sand. 


After considerable experience with mortar, one can tell something 
about its quality by its appearance when wet up, or by trying it with 
a trowel, but practically the architect and owner is in most cases at 
the mercy of the contractor, and about the best that can be done, 
when using common plaster, is to insist on.the best materials, mixing 
in the hair after the lime is cool and giving the contract to an honest 
and intelligent plasterer. 

342. Putting On.—Plastering on lathed work is generally done 
in three coats.* The first coat is called the scratch coat ; the second 
the drown coat; and the third, the whz¢e coat, skim coat or finish. 


On brick or stone work the scratch coat is generally omitted. 
* In the Eastern States dwellings of moderate cost are generally plastered with two-coat work, 


the first or scratch coat being brought out nearly to the grounds, and carefully straightened te 
receive the skim coat, 


LATHING AND PLASTERING. 333 


‘ 


The scratch coat should always be made “rich,” and should con- 
tain plenty of hair or fibre, as it forms the foundation for the brown 
and white coats. This coat is generally put on from 3% to 4 inch 
thick over the laths, and should be pressed by the trowel with suff- 
cient force to squeeze it between and behind the laths, so as to form 
akey or “clinch.” It is this key which holds the plaster to the laths. 
When the first coat has commenced to harden (the time varying from 
two to four days) it should be scored or scratched nearly through its 
thickness with lines diagonally across each other, about 2 to 3 inches 
apart. This gives a better hold to the second coat. 

The first coat should be thoroughly dry before putting on the sec- 
ond coat, but if the surface is too dry it should be slightly dampened 
with a sprinkler or brush as the second coat is put on. 

A great deal of plastering (sometimes called ‘‘ green work”’) is 
done where the brown coat is applied from the same stage, and as 
soon as the scratch coat is puton. When done in this way the scratch 
coat is generally made very rich and the brown coat largely of sand, 
the brown coat being worked into the scratch coat so that it really 
makes only one coat. 

All intelligent plasterers admit that it makes de¢fer work to let the 
scratch coat get dry before the brown is put on, but as it takes more 
labor and also more lime to put on the plaster in this way, they will 
not do it unless it is particularly specified. Besides not giving as 
good a wall, applying the brown coat to the green scratch coat also 
causes the laths to swell badly, which, when they dry, causes cracks 
in the plastering. 

The second or “brown” coat is put on from } to 2 inch thick. 
With this coat all the surfaces should be brought to a true plane, the 
angles made straight, the walls plumb and the ceilings level. 

On the walls the plastering can generally be brought to a true plane 
by means of the grounds, if the latter are set true and the wall is not 
too large or without openings. On the ceilings, however, there is 
usually nothing to guide the plasterer in his work, and the conse- 
quence is that most ceilings, particularly in domestic work, have a 
rolling surface, as can be detected at the edges of the ceiling. 

Screeds.—The only way of obtaining a true plane on ceilings and 
on walls, where the grounds are not sufficient, is by screeding, which 
is done by applying horizontal strips of plaster mortar, 6 to 8 inches 
wide and from 2 to 4 feet apart, all around the room. These are 
made to project from the first coat out to the intended face of the 
second coat, and while soft are made perfectly straight and out of 


334 BUILDING CONSTRUCTION. 


wind with each other by measuring with a plumb, straight-edge, etc. 
When dry the second coat is put on, filling up the broad horizontal 
spaces between them, and is readily brought to a perfectly flat sur- 
face corresponding with the screeds by long straight-edges extending 
over their surface. 

On lathed work, if the studding or furrings have been properly set, 
screeding should not be necessary except on ceilings, but on brick or 
stone walls it is impossible to get true surfaces except by means of 
grounds or screeds. Screeding was formerly done much more exten- 
sively than at present; now it is seldom required except in very 
expensive buildings. Screeding can be done only in three-coat work. 
Before the brown coat becomes hard it should be lightly run over 
with the scratcher to make the third coat adhere better. If part of 
the walls are to be plastered on brickwork and part on laths, the 
scratch coat 1s put only on the laths, and when this is dry the brown 
coat is spread over the whole, including the brickwork. Brick walls 
that are to be plastered should have the joints left rough or open, and 
the walls should- be brushed clean of all dust and slightly dampened 
before putting on the mortar. In very dry weather the brick walls 
should be sprinkled with a hose just before plastering. 

343. Third or Finishing Coat.—The method of finishing the 
wall varies somewhat in different parts of the country, and also with 
the kind of surface desired. In some localities, particularly in small 
villages, when the walls are to be papered, no finishing coat is applied, 
but the brown or scratch coat is smoothly troweled. ‘This reduces 
the expense but a trifle and is not to be recommended, as the walls 
cannot be as well straightened and the roughness of the plaster will 
show through the paper. 

Skim Coat.—In many of the Eastern States the finishing coat is 
called the skzm coat, and is made of lime putty and a fine white sand— 
generally washed beach sand. The lime is slaked and run through 
a sieve into a tight box, and there allowed to stand until it becomes 
of the consistency of putty, when it 1s taken out and the sand mixed 
with it. The box containing the putty should be kept covered to 
keep out dust and dirt, and the putty should not be used until at least 
a week old. 

The skim coat is put on with a trowel, floated down, and then gone 
over with a brush and small trowel until the surface becomes hard 
and polished. In the author’s opinion this makes a much better 
finish than the ordinary wzt¢e coat, although it is claimed that the lat- 
ter is better for walls that are to be painted. 


LATHING AND PLASTERING. 335 


White Coat.—(This term is generally used to designate the finisii- 
ing coat when plaster of Paris is mixed with the lime putty.) In 
most portions of the United States it appears to be the custom to 
finish the walls with a thin coat of lime putty, plaster of Paris and 
marble dust. This makes a whiter wall than the skim coat, and if 
marble dust is used and the work is well troweled it will take a good 
polish. Without the marble dust it will not be as hard nor take a 
polish. For this work the lime is slaked and permitted to form a 
putty, as with the skim coat. The plaster and marble dust should 
not be mixed with the putty until a few moments before using, and 
then only as much should be prepared as can be used up at once, for 
if left to stand any length of time it will “set”? and become useless. 
It should be finished by brushing down with a wet brush and imme- 
diately going over it with a trowel. The more it is troweled the 
harder it will become. In estimating the quantity of materials 
required for the white coat, 90 pounds of lime, 50 pounds of plaster 
and 50 pounds of marble dust should be allowed to 100 square yards. 


Sand Finish—When a rough finish is desired for fresco work, as 
in churches, halls, ete., the third coat is mixed with hme putty and 
sand as for skim coat, except that coarser sand and a greater quan- 
tity of itis used. Sometimes a small quantity of plaster of Paris is 
also mixed with it. Sand finish skould be applied before the brown 
coat is quite dry, and should be floated with either clear, soft pine or 
cork-faced floats. The roughness of the surface desired may be 
conveniently designated by comparing it with the different grades of 
sand paper. 


Sometimes the brown coat is floated to give an imitation of sand 
finish, but it is impossible to get an even and uniform surface without 
using a separate coat. Sand finish is often ruled off and jointed to im- 
itate stone ashlar. It may also be colored as described on page 356. 


HARD WALL PLASTERS. 


344. By using only the best materials and mixing them in the man- 
ner described it is possible to obtain a very good quality of wall plas- 
ter, but there are so many chances of getting an inferior job when 
ordinary “me plaster is used, that a material which can be used with 
greater certainty is very much to be desired. Such a material 
appears to be found in the zmproved wall plasters recently placed on 
the market. 


There are now several improved plasters manufactured by different 


336 BULEOINGGONS TERUG ET OY, 


companies which, although differing in their composition, apparently 
give about the same kind of wall. 

The general name given to these improved or patented wall plas- 
ters is that of “hard wall plaster” or mortar. 

There are two distinct classes of hard plasters, which may be des- 
ignated as natural cement plasters and chemical or patented plasters. 

Natural Cement Plasters.—In this class are the Acme, Aga- 
tite, Aluminite, Climax and Royal, the first and last names being per- 
haps the best known. 

The earth from which these plasters are produced is found in 
various portions of Kansas and Texas. It is of a light ash-gray color 
and of about the consistency of hard plastic clay, which it much 
resembles in appearance, although its chemical nature is more like : 
that of gypsum. 


When calcined it assumes a pulverized form. When mixed with water it sets ike 
hydraulic lime or cement, but much more slowly, so that ample time is afforded for 
applying the mortar. 

A sample of agatite, after several weeks setting, broke under a tensile strength of 
370 pounds per square inch. It is superior in strength to most of the hydraulic limes 
and natural cements.* 


The various deposits from which the plasters above mentioned are 
produced appear to be of about the same grade of earth, the plasters 
differing, if at all, only in their strength and working qualities, which 
is due principally to slight differences in the process of manufacture. 

The Acme cement plaster is produced by calcining the natural 
earth at a high degree of heat (about 600° Fahr.), which rids the 
material of not only the free moisture, but also the combined 
moisture. 

The resulting plaster is slow setting, works smooth under the trowel, 
and does not come to its normal strength until thirty or aah days 
after it is spread. 

These cement plasters are remarkable for their great adhesive 
quality. They will stick firmly to stone, brick or wood without the 
aid of hair or fibre. Acme cement has been used to some extent in 
New York for setting fireproof tiling, and has been found superior 
for this purpose to the ordinary natural cements. 

Acme cement plaster was the first of this class to be put on the 
market. It has been extensively used throughout the country, and 
makes a very superior wall plaster. Large quantities of it were used 
in plastering the World’s Fair buildings, Chicago. Agatite and 





* Professor Edwin Walters, in Kansas City Journal, January 20, 1893. 


» 


LATHING AND PLASTERING. 994 


Vv 


Royal, although more recently introduced, have also been quite 
extensively used, particularly on large and important buildings in the 
West. Climax is produced especially for the Southern trade. 


345. Chemical or Patented Plasters.—In this class are: 
King’s Windsor Cement dry mortar, Adamant, Rock Wall, Granite, 
and some others not so well known. 


The precise composition of these plasters is kept secret, but it is 
generally understood that they are made from gypsum (plaster of 
Paris calcined at about 225° of heat), to which some material or 
chemical is added to vefard the natural quick setting of the plaster 
of Paris and make it slow enough setting that it can be mixed with 
sand and spread upon the wall. As well as the author has been able 
to discover the facts, the difference in these patented plasters is due 
principally to the chemical or other material used for the retarder. 


The first of these plasters, and the first of all hard plasters placed 
on the market, was Adamant. This material was first introduced as 
a substitute for lime plaster at Syracuse, N. Y., in 1886. It is a 
chemical preparation, and the manufacture of the chemicals is cov- 
ered by patents. The chemicals are manufactured exclusively at 
Syracuse, N. Y., by the original company and sold to licensed com- 
panies, who prepare and sell the plaster. There are twenty or more 
of these branch companies scattered throughout the country. The 
Adamant companies claim that the quality of their plaster is due 
principally to the chemicals used in its preparation. Adamant has 
been more extensively used up to this date (1896) than any other of 
the hard wall plasters. 


The Windsor Cement dry mortar is made by mixing certain chem- 
icals with Nova Scotia gypsum of a superior quality to form the 
cement, and the mortar is made by mixing with the cement washed 
and kiln-dried pit sand and asbestos fibre, all the materials being 
accurately weighed and uniformly mixed by special machinery. The 
mortar is made in the vicinity of New York City. It has been exten- 
sively used in many of the best buildings recently built in that city, 
and to a considerable extent elsewhere. 


A preparation, presumably of this class, called Granite Hard Wall 
Plaster, is made in Minneapolis, and similar preparations are made by 
local companies in several localities. 

As far as the author kas been able to ascertain all of these mate- 
rials give good results when properly handled, although those which 
have been longest on the market are apt to be the most reliable. 


338 BOLEDING CONSTROCLION: 


346. How Sold.—All of the plasters above described are packed 
- in sacks, or bags, holding either 100 pounds or a half barrel each. 


Acme, Agatite and Royal are sold in the form of cement only, and 
the sand is mixed with the cement as it is used by the plasterer. 


Two kinds of cement are sold, one mixed with fibre and known 
as fibred cement, and the other without fibre. The fibred cement 
should be used for the first coat on lathed work, whether of wood or 
metal. On brickwork, or fireproof tiling, fibre is not required, and 
the unfibred cement should be used. 


The unfibred cement is also used for second or brown coat and 
wherever the plaster is to be troweled down to a smooth, hard sur- 
face. Where the plaster is to be finished with a white surface it is 
necessary to use lime and plaster of Paris (as on lime plaster) over 
these cements, as they are of a gray color. 


Windsor Cement dry mortar and Adamant are sold mixed with 
fibre and sand, all ready for applying by simply mixing with clean 
water. Two grades of the Windsor mortar are made, one for lath 
work and the other for applying on iron, brick, terra cotta, etc., the 
only difference between the two being that the latter contains more 
sand than the former. Adamant is made in eight different grades 
for base coats on lath, brickwork or tile, for browning coat, and 
for finishing. Four different kinds of finishing material are made, 
to give any style of finish desired. 


347. Application.—The method of applying these plasters does 
not differ materially from that already described for lime mortar, | 
except that the second (corresponding to the brown) coat is put on 
directly after the first coat, and is finished with the darby instead of 
with the float. Being of the nature of cement, or plaster of Paris, 
these mortars se¢ instead of drying, and but little water should be 
used in working them. Only as much material should be mixed as 
can be applied in one and a half hours, and material that has com- 
menced to set should never be remixed. . 

Only clean water should be used, and the tools and mortar box 
should be kept perfectly clean and the box cleaned out after each 
mixing. 

When using the hard plasters on wood laths, the laths should be 
thoroughly dampened, or expanded, before the plaster is spread, so that 
they will not swell after the plaster has commenced to set. Brick, 
stone and tile work should also be well sprinkled before applying 
these mortars. 


v 


LATHING AND PLASTERING. 339 


Most of the manufacturers of hard plasters recommend that when 
their plaster is to be used the laths be spaced only from 4 to } inch 
apart, and that #-inch grounds be used, claiming that a less quantity 
of their material is required than of ordinary lime mortar. 


A gentleman who has had much experience with cement plasters, 
however, says that “ More failures are made in using hard plaster by 
using too thin coats, too weak keys and too weak material (when sold 
unmixed with sand) than from any other cause. 


“To do a good job cf hard plastering it is necessary to use a suff- 
cient amount of cement to give it tensile strength, a good wide key, 
and a good thick coat of plaster. Where it is spread very thin it is 
sure to crack and give an unsatisfactory wall.” 


For lath work a better wall will be- obtained, although at a little 
more expense, by putting on ¢-inch grounds and having a #-inch key. 


All of these plasters, except Adamant, can be finished with a third 
coat, as described in Section 343, which should in no case be applied 
until the base is thoroughly dry. 


Sand finish is generally made by mixing sand with the same plaster 
as is used for the brown coat. 


Full directions for applying the various grades of these plasters are 
furnished. by the manufacturers, and architects should see that these 
instructions are carefully and faithfully followed, as when zmproperly 
applied these plasters are inferior to the ordinary lime mortar. 


348. Advantages.—The principal advantages gained by the use 
of these plasters are: uniformity in strength and quality, greater 
hardness and tenacity, freedom from pitting, less weight and moisture 
in the building, saving in time required for making and drying the 
plaster, minimum danger from frost and greater resistance to fire and 
water. 


Frost does not harm these mortars after they have commenced to 
set or the chemical action has taken place. When used in freezing 
weather they must not le allowed to freeze during the first thirty-six 
hours after applying ; after that time frost will do no harm. 


Those plasters which are already mixed with sand and fibre also 
have the additional advantage of thorough and uniform mixing of 
the materials and absolute correctness of proportion. ‘This latter advan- 
tage is perhaps most appreciated by the architect, as it prevents all 
chance of using a poor quality of sand, or too much of it, and saves 
him a great deal of labor in the superintendence. 


340 BUILDING ‘GONSTROUCTION, 


The benefit to the owner in using these plasters consists in-secur- 
ing much more substantial walls than is possible with the ordinary 
hand-made mortar, less risk from fire and less expense for repairs. 

The slight additional expense of using them is hardly to be consid- 
ered in comparison with the benefits obtained, and it is probable that 
thése plasters will in a short time become generally adopted, they 
being already extensively used‘in the largest and most costly buildings. 

For business buildings the saving in the time required in drying 
the plastering will more than pay for the additional expense. 

On account of their greater density these mortars will not harbor 
vermin nor absorb noxious gases or disease germs, and are therefore 
especially desirable for hospitals, schools, etc. Heat, air and moist- 
ure will not pass through them as through lime plaster. 

A wall of hard plaster, wood or metal lath is also much more 
resonant than one of lime mortar, and for this reason, and also on 
account of their greater strength, these mortars should be especially 
valuable for plastering churches, opera houses and public halls. 


S LUGO ORK 


349. This term, as commonly used in this country, refers to orna- 
mental interior plaster work, such as cornices, mouldings, centre- 
pieces, etc. For such work a mixture of lime paste and plaster of 
Paris is used, except for cast work, which is made entirely of plaster 
of Paris. 

Plaster of Paris is produced by the gentle calcination of gypsum to 
a point short of the expulsion of the whole of the moisture. Paste 
made from it sets in a few minutes, and attains its full strength in an 
hour or two. At the time of setting it expands in volume, which 
makes it especially valuable for taking casts and for making cast 
ornaments for walls and ceilings, and also for patching and repairing 
ordinary plaster work. 

When added to lime mortar, plaster of Paris causes the mortar to 
set or harden very quickly, and for this reason it is often mixed with 
mortar to be used for patching or repairing, or where itis necessary 
to have the plaster harden very quickly. When this is done it is 
called “ gauged work.” 

Plaster of Paris is very hable to crack when used clear and in con- 
siderable thickness. Cast ornaments made of it are therefore usuaily 
made hollow, or with a thin shell. For work that is to be run, or 
worked by hand, it cannot be used clear, as it sets too quickly. itis 
for this reason that lime putty is mixed with it. | 


LATHING AND PLASTERING. 341 


For mouldings, cornices, etc., about 2 parts of plaster of Paris to 1 
of lime paste is used. 

Plain mouldings, whetner in a cornice, centrepiece, or on the wall 
or ceiling, are usually “run” in place by hand. The process con- 
sists in placing on the ne of the wall or ceiling a sufficient body 
of plaster and forming the mould by running along it a sheet iron 
template, cut to the reverse profile of the mould. The template is 
stiffened by wooden cleats, and provided with struts to keep the plane 
of the template always perpendicular to the plane of the surface on 
which the mould is run. The stucco work is always run before the 
















WK) 


y= 


Ga 


NM 


Fig. 232. 


finishing coat of plaster is applied, as it is necessary to fasten light pine 
straight-edges on the wall to form guides for the templates. In run: 
ning the moulding two men are generally required, one to put on the 
plaster as it is needed and the other to work the template, which gen- 
erally has to be worked back and forth several times before the 
moulding is finished. 

The whole moulding or cornice between any two breaks or pro- 
jections should be completed at once, so that the entire length may 
be uniform in shape and shade. 

The mitres at the angles, both internal and external, have to be 
finished by hand, using a small trowel and straight-edge. 


See Ra BUILDING CONSIEUCTILION: 


If the cornice or moulding contains much ornamental work, it 
is cheaper to cast it in sections of about 2 feet in length, and attach 
to the wall by means of liquid plaster of Paris. It requires great 
care in cast work to have the sections join nicely, so that the mem- 
bers will present a perfectly straight line. 

If there are only one or two enriched members, the rest of the 
moulding or cornice may be run in the usual way, leaving sinkings to 
receive the enriched mem- | 
bers, which are then cast 
and stuck in place, as at 
od Hips 32. 

In designing cornices 
or belt mouldings, care 
should be taken not to have over 3 inches in thickness 
of plaster at any point. If the mouldings have greater 
than this the wall or angle should be blocked and 
lathed, as in Fig. 232, so as to reduce the amount of 
plaster required to a minimum. When the projection 
is only about 34 or 4 inches, the back may be formed 
of brown mortar (Fig. 233), containing a little plaster 
of Paris, and held in place by projecting spikes or 
large nails, driven into the wall or ceiling before the 
mortar is put on. 

Centre ornaments, when consisting only of plain cir- 





cular mouldings, are run in the same way as other 
moulded work, except that the template is attached to 
a piece of wood which is pivoted at the centre of the 
ornament. Enriched centres are cast in a mould and 
‘stuck to the ceiling after the finish coat is on. 

All kinds of ornaments, such as paneled ceilings, 
bas-reliefs, imitations of foliage, etc., may readily be 
executed in plaster of Paris, and when the ornament is placed in 
such positions that it cannot readily be injured by objects in the 
room, it answers as well as harder and more expensive materials. 

Since hard wood finish has become so prevalent, however, it has 
largely supplanted the plaster cornices that were so common fifty 
years ago. 

Stucco work is generally included in the plasterer’s specifications. 
As it is much more expensive than ordinary plastering, the quantity 
and character of it should be clearly indicated on the drawings and 
in the specifications, and by full size details. 


Fig. 2.3. 


LATHING AND PLASTERING. 343 


For enriched work the architect should require that the models be 
approved by him before the casts are made. 

350. Keene’s Cement.—When it is desired to finish plaster 
walls, ceilings, columns, etc., with a very hard and highly polished 
surface, Keene’s cement is generally used for the finishing coat. 
This cement is a plaster produced (in England) by recalcining plas- 
ter of Paris after soaking it in a saturated solution of alum. This 
material is very hard and capable of taking a high polish, and walls 
finished with it may be sponged with soft water without injury. 

It is especially valuable for finishing plastered columns, the lower 
pertions of walls, and wherever the plaster is liable to injury from con- 
tact with furniture, etc. It is also used in the manufacture of artifi- 
cial marbe. 

The manufacturers of King’s Superfine Windsor Cement claim that 
for finishing walls it is equal to the imported Keene’s cement; it is 
considerably less expensive. 

Neither of these materials should be used in situations much 
exposed to the weather, on account of their solubility. 

351. Scagliola is a coating applied to walls, columns, etc., to 
imitate marble. The base or ground work is generally of rich lime 
mortar containing a large proportion of hair. After this has set and 
is quite dry it is covered with a floated coat, consisting of plaster of 
Paris or Keene’s cement, mixed with various coloring matters in a 
solution of glue or isinglass, to give greater solidity and to prevent 
the plaster of Paris from setting too quickly. When the surface is 
thoroughly hard it is rubbed with pumice stone and then polished 
until it looks like polished marble. Columns can be made in this 
way that can hardly be detected by the eye from marble. 

Imitation marble, when in flat slabs, is commonly made on sheets 
of plate glass. Threads of floss silk, which have been dipped into 
the veining colors, previously mixed to a semi-fluid state with plaster 
of Paris, are placed upon a sheet of plate glass so as to resemble the 
veins in the marble to be imitated. Upon this the body color of the 
marble is placed by hand. The silk is then withdrawn and dry plas- 
ter of Paris is sprinkled over to take up the excess of moisture and 
to give the plaster the proper consistency. A backing of cement or 
plaster of Paris is then applied of any desired thickness. Canvas is 
sometimes placed in the backing to give greater strength. After 
removing from the glass the slab is polished and set in place in the 
same manner as the genuine material. This work naturally requires 
much skill in the workman, besides practice and experience 


344 BUILDING CONSTRUCTION. 


A great deal of scagliola has been used in Europe, and in recent 
years several companies have been formed in America for making 
artificial marble, which is essentially the same thing. For interior 
work scagliola should be as durable as marble, and there are columns 
of it in Europe several hundred years old. It should not be used on 
the exterior of buildings, as it will not bear exposure to the weather. 


352. Fibrous Plaster consists of a thin coating of plaster of 
Paris on a coarse canvas backing stretched on a light framework 
and formed into slabs. For casts about } inch of plaster is put in 
the mould, and the canvas is then put on the back and slightly 
pressed into the plaster. Fibrous plaster is very light and strong, 
and can be easily handled without breaking. It is extensively used 
in England for ornamental work, and in Brazil it is said to be used 
extensively for external work. 


Carton Pierre is a material used for making raised ornaments for 
wall and ceiling decoration. It is composed of whiting mixed with 
glue and the pulp of paper, rags and sometimes hemp, which is forced 
into plaster or gelatine moulds, backed with paper, and then removed 
to a drying room to harden. It is much stronger and lighter than 
common plaster of Paris ornaments, and is not so liable to chip or 
break if struck with anything. 


Ornaments of carton pierre (under different names) are now exten- 
sively used in this country for decorating rooms, mantels, etc., and 
also to some extent on the exterior of buildings. If kept painted 
there appears to be no reason why it should not last for many years, 
except in very exposed positions. 


EXTERNAL PLASTERING. 


353. This is generally either rough-cast or stucco. The first is a 
description of coarse plastering, generally applied on laths ; the sec- 
ond is a description of plastering on brickwork, executed so as to 
resemble stone ashlar. 

Rough-cast has been extensively used in Canada, and to some 
extent in the Northern States. It is said to be much warmer than 
siding or shingles, less expensive, and quite as durable. It is also 
more fire-resisting. 

“There are frame cottages near the city of Toronto and along the 
northern shores of Lake Ontario that were plastered and rough-casted 
exteriorly over forty years ago, and the mortar to-day is as good and 
sound as when first put on, and it looks as though it was good for 


LALHING AND PLASTERING. 345 


many years yet if the timbers of the building it preserves remain 
good. 

‘““Tt is quite a common occurrence in Manitoba and the northwest 
Territories in the winter to find the mercury frozen, yet this intensity 
of frost does not seem to affect the rough-casting in the least, though 
it will chip bricks, contract and expand timber and render stone as 
brittle as glass in many cases.” * 

Frame buildings to be rough-casted shoud be covered with sheath- 
ing and one thickness of tarred paper. The partitions should be put 
in and even lathed before the outside is plastered, as it is important 
to have the building stiff and well braced. 

The best mode of rough-casting, as practiced in the lake district of 
Ontario, is said to be as follows: 


Lath over the sheathing (or tarred paper if used) diagonally with No. 1 pine laths, 
keeping I; inches space between the lath; nail each lath with five nails and break 
joints every 18 inches; over this lath diagonally in the opposite direction, keeping 
the same space between the laths and breaking joint as before. Careful and solid 
nailing is required for this layer of lathing, as the permanency of the work depends 
to some extent on this portion of it being honestly done. The first coat should con- 
sist of rich lime mortar, with a large proportion of cow’s hair, and should be mixed 
at least four days before using. The operator must see to it that the mortar be well 
pressed into the key or interstices of the lathing to make it hold good. The face of 
the work must be well scratched to form a key for the second coat, which must not be 
put on before the first or scratch coat is dry. The mortar for the second coat is made 
the same as for the first coat, and is applied in a similar manner, with the exception 
that the scratch coat must be well damped before the second coat is put on, in order 
to keep the second coat moist and soft until the dash or rough-cast is thrown on. 

The dash, as it is called, is composed of fine gravel, clean washed from all earthy 
particles and mixed with pure lime and water till the whole is of a semi-fluid con- 
sistency. This is mixed in a shallow tub or pail and is thrown upon the plastered 
wall with a wooden float about 5 or 6 inches square. While the plasterer throws on 
the rough-cast with the float in his right hand, he holds in his left a common white- 
wash brush, which he dips into the dash and then brushes over the mortar and 
rough-cast, which gives them, when finished, a regular uniform color and appearance. 

For 100 yards of rough casting, done as above described, the following quantities 
will be required: 1,800 laths, 12 bushels of lime, 14 barrels best cow hair, 13 yards 
of sand, 3 yard of prepared gravel and 16 pounds of cut lath nails, 1} inches long. 
A quarter barrel of lime putty should be mixed with every barrel of prepared gravel 
for the dash. The dash may be colored as desired by using the proper pigments. 

To color 100 yards in any of the tints named herewith use the following quanti- 
ties of ingredients: For a blue-black, 5 pounds of lampblack ; for buff, 5 pounds of 
green copperas, to which add 1 pound of fresh cow manure, strained, and mixed with 
the dash. A fine terra cotta is made by using 15 pounds of metallic oxide, mixed 





* ** Rough Casting in Canada,”’ by Fred. T. Hodgson, Architecture and Building, March 24, 
1894. 


346 BUILDING CONSTRUCTION. 


with 5 pounds of green copperas and 4 pounds of lampblack. Many tints of these 
colors may be obtained by varying the quantities given. The colors obtained by 
these methods are permanent ; they do not fade or change with time or atmospheric 
variations. Earthy colors, like Venetian red and umber, soon fade and havea sickly 
appearance. 


Expanded metal, perforated, or stiffened wire lathing are undoubt- 
edly better than wood laths for external plastering, as they hold the 
plaster better and also afford greater protection from fire. 

The following description of external plastering, as used by an 
architect of considerable experience with this sort of work, was pub- 
lished in the Brickbuilder for August, 1895, and probably ae OAS 
the best current practice in this country : 


I have always used three-coat work, the first well-haired mortar and one-third 
Portland cement, added when ready for use ; this coat well scratched. The second 
coat the same, with the omission of the hair, and the third coat the same proportion, 
but with coarse sand or gravel, either floated or put on slap-dash, according to the 
kind of finish I wished to obtain. 

I have occasionally used a very small quantity of ochre -in this. last coat, but it 
must be mixed very thoroughly and carefully in order to produce an even color. 

This plaster work I have used on wood lath over stud without rough boarding 
behind it. Also on rough boarding with furrings and wood lath, which is better ; 
and over rough boarding with furrings and wire lath, which is the best of all. 

A small church plastered in this way on wood lath fourteen years ago is in perfect 
condition to-day, and various houses built during the last ten years have proved per- 
fectly- satisfactory. I have not as yet, however, found any method of building true 
half-timbered work and making it thoroughly tight without making a wall that was 
practically as expensive as a brick wall. 


354. External Stucco.—External plastering of buildings was at 
one time greatly in vogue in European countries, and there are many 
examples of “stucco’’-covered buildings in the older portions of this 
country. Formerly lime and sand were used for the purpose, but this 
material is not very durable. If it is desired to plaster a brick build- 
ing to imitate stone ashlar, Portland cement is the only material that 
should be used. It should be mixed with clean sharp sand, not too 
fine, in the proportion of 3 parts sand to 1 of cement. The wall to 
be covered should itself be dry, but the surface should be well wet 
down with a hose to prevent it from absorbing at once all the water 
in the cement ; it should also be sufficiently rough to form a good key 
for the cement. Screeds may be formed on the surface, and the 
cement should be filled out the full thickness in one coat and of uni- 
form substance throughout. When cement is put on in two or three 
coats, whether for exterior or interior work, the coats already applied 


LATHING AND PLASTERING. 347 


should on 2o account be allowed to dry before the succeeding layers are 
added, otherwise they are quite sure to separate. 

The manufacturers of Acme cement plaster claim that where brick 
buildings are to be plastered with cement on the outside, that their 
plaster is superior to Portland cement for the first coat, as it adheres 
more firmly to the brick, and will hold the Portland cement and the 
base upon which it is spread together. 

The cement may be marked with lines to represent stone ashlar 
before it becomes hard. If it is desired to color the cement, mineral 
pigments must be used, such as Venetian red or the ochres. The 
natural color of the cement may be lightened by the addition of a 


very little lime. 
STAFF.* 


355. Staff, a material used for the exterior covering of all the 
buildings of the World’s Columbian Exposition at Chicago, may be 
considered as almost a new material in this country, although it has 
been in extensive use in Europe for many years. A large part of all 
exterior decoration of buildings, both public and private, in the pro- 
vincial cities of Germany, whether ornament, columns or statuary, 
is made of staff, and in instances a period of fifty years of existence 
will testify to its enduring qualities. Staff was first used extensively 
in the construction of buildings at the Paris Exposition of 1878, and 
it was also adopted in work on the much grander buildings of the ex- 
position of 1889. The methods of application at these expositions 
were, however, widely different from and much more expensive than 
those employed at the Columbian Exposition. 

The staff for the World’s Fair buildings was made on the grounds 
at Jackson Park in the following manner : 


The ingredients were simply plaster of Paris, or Michigan plaster, water and hemp 
fibre. Hemp was used to bind together and add strength to the cast, and the New 
Zealand fibre was preferred, as both the American and Russian fibres were found too 
stiff. The first step in making staff ornaments is the creation of a clay model. The 
model is heavily coated with shellac, and a layer of clay separated from the model 
by paper is put on its face and sides. This layer of clay is oiled or greased and a 
heavy coating of plaster and hemp is put over it. The thickness of this coating is 
dependent upon the size of the model; sometimes it is 5 or 6 inches thick and con- 
tains heavy battens of wood to strengthen it. In less than twenty-four hours this 
coating is hard and is taken off the clay covering the model. The coating thus 
removed is called the box. Next the clay is removed from the model and the model 


* The following description of this material is taken from an article by E. Phillipson, pub- 
lished in the Engineering Record of June 4, 1892. Mr. Phillipson had charge of this portion of 
the work on the World's Fair buildings. 


348 BUILDING CONSTRUCTION. 


is thoroughly oiled. The box is oiled and put over the model. leaving the space 
between model and box formerly taken up by the clay coating a free space. Holes 
have previously been made in the box, and upon a large centre hole (sometimes two or 
three in large pieces) a plaster funnel is placed. Molten gelatine is poured through 
these funnels, which fills every space, air being allowed to escape through small holes 
in the box. In from twelve to twenty-four hours the box is again removed, placed 
hollow side up, and the now hardened gelatine is removed from the clay model and 
placed in the box, which it fits perfectly. The clay model has now served its pur- 
pose, for the gelatine, which has become a matrix of the cast desired, is used in the 
further stages of the work. In case of large moulds the gelatine matrix is sometimes 
cut into as many as eight pieces. Ali these, of course, join perfectly in the box and 
are cast from as if froma single matrix. The gelatine mould is washed a number of 
times with a strong solution of water and alum. and after oiling is ready for the oper- 
ation of casting. 

The plaster for the staff is thoroughly stirred in water, and the hemp, cut into 
lengths of 6 to 8 inches, is bunched loosely, saturated with the plaster and put in the 
moulds in a layer of about I inch in thickness. Succeeding handfuls of hemp are 
thoroughly interwoven with the preceding, the hemp being expected to fill in all the 
corners of the cast. When the mould is filled the back is smoothed over by hand, 
and later the cast is removed from the mould. The time consumed from starting a 
cast to removing it from the mould, is for a cast 5’x2'6" in size, about twenty-five 
minutes. After the removal of the cast care must be exercised in either standing it 
up or laying it down that it shall not collapse or lose its form by warping. During 
the summer months a cast of the dimensions given will dry thoroughly in about 
thirty-six hours and is then ready for application. In the winter months there is 
danger of casts freezing before they are dry, and in that event they are apt to go to 
pieces when warm weather comes. A good workman can make as many as seventy- 
five casts in one mould, and then the gelatine is remelted and a new mould made of 
it, the box being good for use for an indefinite length of time. In making pilasters 
or mouldings, etc., not ornamented or under-cut, plaster and wood moulds are often 
used, the latter material being especially preferred, owing to its durability. 


“Applied to a frame building, staff is simply nailed on to the rough 
construction, and a cheap brick wall covered with it can, at a com- 
paratively small expense, be made to assume a classic appearance, 
In building a brick house with the employment of staff in view, it is 
advisable to insert wooden furring strips in the brick, as these sim- 
plify the labor of putting it on. For cornice work it is claimed that 
a strength and boldness of design are possible with staff which cannot 
be realized with other materials. 


“At the Paris Exposition the buildings were constructed almost 
entirely of iron, and nearly all the staff was cast in panels, which 
were set iniron frames. While this method was considered excellent, 
both in finished effect and in durability, it was far too expensive and 
tedious to be employed in covering the much more extensive struc- 
tures to be built for the World’s Columbian Exposition Accord- 


LATHING AND PLASTERING. 349 


ingly, after many weeks of study, the construction department decided 
to construct the buildings of wood and to nail the staff directly to the 
furring. 

‘«The name ‘staff’ properly applies to material that is cast in moulds, and not to 
ordinary plaster or cements that are put on with a plasterer’s trowel. Work with such 
materials is subject to well-understood limitations by the temperature and weather, 
but atmospheric influences have practically no effect upon staff. This has been 
demonstrated by the acres of staff that has been standing all winter outside the various 
casting shops in Jackson Park. No attempt has been made to keep off the rain, 
snow or frost. Several pieces of it have been submerged for over a month at a time, 
allowed to freeze and thaw, and freeze again with the water, and when taken out 
they were found to be perfectly intact.” 


While this material admirably answered its purpose on the Fair 
buildings, it became considerably deteriorated, and evidently would 
not answer in such a climate for permanent buildings unless kept well 
painted. In fact, it appears to be generally conceded that Portland 
cement is about the only material that will endure permanently under 
the trying conditions of our northern climate. In warmer and dryer 
climates compositions of plaster are largely used on the exterior of 
buildings, and in many instances they have lasted for centuries. 


The cost of “staff,” as used on the World’s Fair buildings, varied 
from $2 to $2.25 per square yard. Ordinary cement mortar applied 
directly to the walls cost about thirty cents per yard. 


356. Whitewashing.—Although not properly belonging to the 
plasterer’s trade, this work is often included in the plasterer’s specifi- 
cations. 

Common whitewash is made by simply slaking fresh lime in water. 
It is better to use boiling water for slaking. The addition of 2 
pounds of sulphate of zinc and 1 of common salt for every half 
bushel of lime wiJl cause the wash to harden and prevent its crack- 
ing. One pint of linseed oil, added to a gallon of whitewash imme- 
diately after slaking, will add to its durability, particularly for outside 
work. Yellow ochre, lampblack, Indian red or raw umber may be 
used for coloring matter if desired. 

Whitewash not only prevents the decay of wood, but conduces 
greatly to the healthiness of all buildings, whether of wood or stone. 
It does not adhere well, however, to very smooth or non-porous sur- 
faces. ‘Two coats of whitewash are required on new work to make 
a good job. 


350 BUILDING CONSTRUCTION. 


LATHING AND’ PLASTERING IN FIREPROOF 
CONSTRUCTION. 


357. Wherever lathing is required in buildings that are intended 
to be thoroughly fireproof, only stiffened wire or expanded metal lath 
should be used. If one of the hard 
plasters are to be used, close-warp 
(2$x5 mesh) should be specified, 
and the lathing should be either 
painted or galvanized. (See Sec- 
tion 333.) 

In builé‘ngs having hollow tile 
floor construction but very little, if 
any, lathing is used, as all the 
walls, ceilings and partitions are of 
tile, on which the plastering is directly applied. For such buildings 
either machine-made lime mortar (such as is described in Section 
340) or one of the hard plasters should be used. 





Fig. 234. 


Cornices, false beams, etc., in this class of buildings are more 


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commonly formed by furring with light iron and covering with metal 
lath, to which the plastering is applied. 

The method of forming a beam and cornice in this way is shown 
by Fig. 234. The general profile is formed by bending light iron by 


LALGMANG AND PLASTERING. 350a 


hand on a shaping plate to the desired outline. These are secured 
in position and longitudinal rods fastened to their angles, after which 
the wire lathing is applied. 

Fig. 235 shows the manner of furring steel and iron columns 
when protected by wire lath and plaster, and Fig. 235@ a popular 
method when expanded metal is used. 

Both wire lath and expanded metal have been very extensively 
used for furring elaborate ceilings, beams, arches, vaults, etc., in 
public buildings, and wherever such furring has been removed or 
examined after a term of years, it has always, so far as known, been 
found to be in good condition and free from rust. 

The larger portion of the plaster beams and ceilings, domes, etc., 
of the new Congressional Library are formed with expanded metal 
on iron furrings, also the 
very elaborate ceiling of the 
dining room in the Chicago 
Athletic Club and the domes 
and paneled ceilings of the 
New York Clearing House. 
In the main corridor of the Worthington Building in 
Chicago an elaborate vaulted mosaic ceiling is supported 
by a background of hard mortar on expanded metal. 

The extent to which both wire lath and expanded 
metal may be used in forming a base for mortar and cement 
appears to be unlimited. When hollow tiles are used for 
fireproofing, the grounds for the cornices are sometimes 
formed of terra cotta, as shown in Fig. 236. Such grounds » 
are more firm to carry the heavy stucco, and the plastering is not as 






liable to be broken by streams of water in case of fire. They are, 
therefore, generally preferred to metal grounds, and are used almost 
entirely in the U. S. Government buildings when the ceilings are 
of tile. : 

The various pieces forming the ground should be bolted to the 
floor construction with }-inch T-head bolts spaced not over 12 inches 
apart longitudinally, and at least two bolts to each piece. 

These terra cotta grounds are usually made by manufacturers of 
flue linings and pipes, as their machinery is better adapted for the 
purpose than that used for making fireprooof tile. 

358. Thin Partitions of Metal Lath and Studding.—As 
stated in Section 320, partitions only 2 inches thick are now quite 
extensively used in office buildings and hotels to economize floor 


350d BUILDING CONSTRUCTION. 


space. Most of these partitions are constructed of upright studding 
of ?-inch channel bars spaced from 12 to 16 inches on centers and 
fastened securely to the floor and ceiling. On one side of this stud- 
ding, metal lathing, preferably of stiffened wire cloth, or expanded 
metal, is stretched and securely laced to the studs. The partition is 
then plastered on both sides with hard plastering and finished in the 
usual manner. If properly executed the partition will be stiff enough 
to answer all the purposes for which it is required, and is, of course, 
absolutely fireproof. Only the best of hard wall plasters should Le 
used for such partitions, however, as the stiffness of the partition de- 
pends very much upon the solidity of the plastering; hence the firmer 
and harder the plastering the more substantial will be the walls. By 
using 2-inch channels and lathing both sides 
a very stiff partition is obtained, but, of 
course, at greater expense. 

The New Jersey Wire Cloth Co. makes a 
special lathing for thin partitions, which 
has a }-inch solid rod woven in at intervals 
of 74 inches. The lath is stretched over 
the studs so that the rods cross them at 
right angles. The lath, after being tightly 
stretched, is laced to the studs at every 
point where the rods cross them. 

Expanded metal has been very exten- 
sively used in the construction of solid par- 
titions. It is applied the same way as 
wire lath (by soft steel wire), except that be- 
ing in flat sheets it does not require stretch- 
ing. Perforated sheet metal lathing, when used, is generally secured 
to the studding by trunk nails driven through the lath along side of 
the stud and clinched around behind it, each nail being driven on 
the opposite side of the stud from the one above and below. 

Provisions for Base and Picture Mould—If wire lath of the 
standard mesh is used some provision must be made for securing 
the wooden base and picture mould. 

Fig. 237 shows the method ordinarily adopted for securing the 
base. For securing the picture mould, strips of wood may be laced 
to the lath at the required height before plastering. 

When imbedded in the plaster these strips are sufficiently firm to 
hold the picture mould. The mould should be put up with screws, 
however, and not with nails. 





LATHING AND PLASTERING. 351 


When close-warp lathing, plastered with mortar, is used, No. 14 or 
16 screws will engage in the meshes of the wirework, and all wood- 
work can be fastened directly 
to the partition with wood 











Yj screws. 
YY, 
Y.5.—OK Door and Window Fram- 
C itdatN WW Te Th l hod of 
I~ ing.—The usual method o 
Yf framing for doors and win- 
lijUy dows has been to set up 
rough wood frames, to which 
the adjoining channel is se- 
curely fastened by screws or 
anchor nails, and in most 
cases this method is quite 
satisfactory. 








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_ fs 
YY JJJYYZYWwCVFK 


Fig. 237a@ shows various 
styles of door frames, which 
differ principally in the char- 
acter of the finish. Those 
sections which have the 
widest door jambs will be 
found the stiffest. Various 
modifications of these details 
may be made to suit the judg- 
ment or taste of the archi- 
CECK. 


Fig. 2376 shows one 
method of constructing the 
window frames in corridor 
partitions. The style of 
moulding may be varied to 
suit the taste of the designer. 


In warehouses where there 
is to be heavy trucking, or 
where iron or fireproof doors 
are to be used, the door 
frame may be built of 14x14- 
inch angle iron, to which the 
first stud of the partition should be riveted. 


In extremely large doorways and on freight elevators it is often a 


he: BUILDING CONSTEROGUCTION. 


practice to make the frames of heavy 2-inch channel iron, to which 
are hung the large fireproof doors. 

Partitions of thin porous tiling were described in Chapter IX., 
Section 320. 

For forms of specifications for solid partitions see pages 389 and 390. 









<2 > 
Y 


\ ee 







LLYN 


Fig. 2370. 


PLASTERING SUPERINTENDENCE. 


359. This consists chiefly in seeing that the work is performed in 
accordance with the specifications, and if the specifications are prop- 
erly written much of the vexation of superintendence will be saved. 
The points which the superintendent should particularly inspect are 
the following : 


Quality of Materials.—See that the laths are of the kind specified, 
and, if of wood, that they are free from bark and dead knots. If any 
such laths have been put on have them removed and clean, sound 
laths substituted. See that the lime is of the kind specified ; if it is 
not in casks it will be well to require the plasterer to produce the 
bills for the lime; also that the lime is fresh and in good condition. 
Permit no lime that has commenced to slake to be used. Inspect the 
sand to see that it is free from earthy matter, and that it is properly 
screened. Make a note of the time the plasterer commences to make 
the mortar, and do not permit him to use it until it 1s at least seven 
days old, or as required by the specifications. 


As to the proportions of the lime, sand and hair, not much can be 
told by the superintendent, unless he has the quantities measured in 
his presence, which will involve his being on the ground most of the 
time. Something, however, of the quality of the mortar and of the 
amount of hair may be determined by trying it with a trowel. The 
superintendent should endeavor to make hiniself familiar with the 
appearance of good mortar. See that the hair is mixed with the 


LAVHING AND PLASTERING. 353 


mortar at the stage specified, and in no case permit it to be mixed 
with the hot lime. 

Lathing.—Before the workmen commence to put on the laths the 
architect or superintendent should carefully examine all grounds and 
furring to see that they are in the right place and are plumb and 
square. If the chimney-breasts are furred, as is the custom in the 
Eastern States, they should be tried with a carpenter’s square to make 
sure that their external and internal angles are right angles; also see 
that all angles of partitions are made solid, so that there can be no 
lathing through the angles. 

If wooden laths are used, see that they are well nailed and that 
they are not placed too near together ; 3 of an inch should be allowed 
on ceilings and +} to 3°, on walls. 


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Fig. 238. Fig. 239. 


See that the end joints are broken at least every 18 inches; if the 
lather will do so, it is better to break joint in every course. 

See that the laths over door and window heads extend at least to 
the next stud beyond the jamb (as in Fig. 238), so as to prevent 
cracks which are apt to appear at that point; also see that all the 
laths run in the same direction. When laths run in different direc- 
tions (as in Fig. 239) cracks are sure to appear where the change 
takes place. See that all recesses ip brick walls for pipes, etc., are 
covered with wire or expanded metal lathing, unless they are to be 
covered with boards. 

Also see that all wood lintels and other solid timbers that are not 
furred are covered with metal lath. The juncture of wood with 
brickwork should also be covered with metal lathing. If any kind 


354 BUILDING CONSTRUCTION. 


of metal lathing is used see that it is put up as directed by the man. 
ufacturers, and that all wire lathing is tightly stretched ; see that the 
furrings are properly spaced and that the whole is well secured. 

Before the plasterers commence work the superintendent should 
see that the building is closed in by the carpenter, either by filling the 
openings with boards, old sash or cloth. Cotton cloth is the best 
material for the purpose, as it permits of some circulation of air 
through it. 

If the plastering is done in cold or freezing weather provision must 
be made for heating the building. Ordinary lime plaster is com- 
pletely ruined by freezing and thawing, and plastering that has once 
been frozen will never become hard and solid. 

When the scratch coat is partly on the superintendent should try 
to look behind the laths to see if the mortar has been well pushed 
through between them, as the clinch, or key, at the back of the laths 
is all that holds the plaster in place. 

See that the first coat is dry before the second is put on, if so spec- 
ified ; also that the surface of the brown coat is brought to a true 
plane, the angles made straight and square, the walls plumb and the 
ceilings level. The specifications should require that the first and 
second coats be carried to the floor, behind the base or wainscoting. 

When brick walls are to be plastered the superintendent should 
remember that a much firmer job of plastering will be obtained if the 
wall is well wel just before the plastering is applied. 

If the first and second coats have been properly put on the finish 
coat will need little superintendence beyond seeing that proper 
materials are used and that the work is well troweled, if hard finish. 

If any of the improved plasters described in Sections 344-5 are 
used, the superintendent should see that the instructions furnished by 
the manufacturers are strictly followed, particularly as to the wetting 
of the laths and the proportion of sand used ; he should also see that 
no mortar that has commenced to set is remixed. When machine- 
made lime mortar, or any of the hard plasters that are sold already 
mixed with sand and fibre, are specified, the care of superintendence 
will be greatly lessened. If improved plasters are used in freezing 
weather the building must be kept above the freezing point until the 
plaster has set. 

360. Measuring Plaster Work.—Lathing is always figured 
by the square yard and is generally included with the plastering, 
although in small country towns the carpenter often puts on the laths. 

Plastering on plain surfaces, as walls and ceilings, is always meas-’ 


LATHING AND PLASTERING. 355 


ured by the square yard, whether it be one, two or three-coat work, 
or lime or hard plaster. 


In regard to deducting for openings, custom varies somewhat in 
different portions of the country, and also with different contractors. 
Some plasterers allow one-half the area of openings for ordinary doors 
and windows, while others make no allowance for openings less than 
7 square yards. 


Returns of chimney breasts, pilasters and all strips less than 12 
inches in width should be measured as t2 inches wide. Closets, sof- 
fits of stairs, etc., are generally figured at a higher rate than plain 
walls or ceilings, as it is not as easy to get at them. For circular or 
elliptical work, domes or groined ceilings, an additional price is also 
made. If the plastering cannot be done from tressels an additional 
charge must be made for staging. 


Stucco cornices or paneled work are generally measured by the super- 
ficial foot, measuring on the profile of the moulding. When less than 
12 inches in girth they are usually rated as 1 foot. For each internal 
angle 1 lineal foot should be added, and for external angles, 2 feet. 


For cornices on circular or elliptical work an additional price 
should be charged. 


Enriched mouldings are generally figured by the lineal foot, the 
price depending upon the design and size of the mould. 


Whenever plastering is done by measurement the contract should 
definitely state whether or not openings are to be deducted, anda 
special price should be made for the stucco work, based on the full 
size details. 


361. Cost.—The cost of lime plastering on plain surfaces, includ- 
ing wooden laths, varies from twenty to thirty-five cents per yard, 
according to the times, locality, number of coats and quality of work. 
For ordinary three-coat work, with white finish, twenty-five cents is 
probably about the average price for the entire country. The author 
has known very good work to be done at twenty cents per yard, but 
there was no profit above the wages of the men. 

Hard plasters cost from two to ten cents per yard more than lime 
plaster, according to the price of lime and freightage on the hard 
plaster. 

Wire or metal lathing will cost from twenty-five to torty cents per 
yard more than if wood laths were used. 


356 BOILDING GON STROGLTTON: 


The following figures give the average price for various kinds of 
plastering in the cities of New York and St. Louis : 


AVERAGE COST IN CENTS 


DESCRIPTION OF WORK. PER SQUARE YARD. 


Lime Mertar: New York. | St. Louis.* 
iT wo-coat work: on DrICk-OF til@..55, ocess a aces « 30 to 35 17 to 21 
1Three-coat work on wood laths........ o's: aisha sie, abe 35 to 40 20 to 25 
1Three-coat work on stiffened wire lath®.......... 70 fe 
1Three-coat work on expanded metal*®............. e 55 

2Windsor Cement or Adan.ant on brick or tile........ 40 bef 

Acme or Royal cement plaster on brick or tile....... 40 22 to 26 

?Windsor Cement or Adamant on stiffened wire lath®.. 75 Se 

2 Acme or Royal cement plaster on stiffened wire lath®. 75 60 

Cost of stiffened wire lath on wood joist, about....... 35 Ge 

Cost of expanded metal on wood jorst.c. 2... steele 24 30 

Cost of Bostwick lath on wood joist......-...e02.++-- — 25 

Stucco cornices, less than 12 inches girth, per lineal foot. 20 20 

When more than 12 inches girth, cost per square foot.. 24 20 


Enrichments cost from 8 cents up per lineal foot for 
each member. 


1. The last coat to be white finish. 

2. Finished with lime putty and plaster. 

3. When applied on wood joist or furring : when applied over metal furrings the cost is about 
20 cents per yard more. 


For scratch and brown coats on wood laths, with 3-inch grounds, 
the following quantities of materials should be required to 100 square 
yards: 1,400 to 1,500 laths, 10 pounds of three-penny nails, two and 
one-half casks or 500 pounds of lime, 45 cubic feet or fifteen casks 
of sand and four bushels of hair. 

For the best quality of white coating allow 90 pounds of lime, 50 
pounds of plaster of Paris and 50 pounds of marble dust. 

Colored Sand Finish.—In most instances where sand finish is 
used on interior walls, it is with the purpose of afterward decorating 
in water color. In such cases the finish itself may be colored or 
stained at a slightly less expense than with water color, and with the 
advantage that, the finish being stained throughout its entire mass, 
dents and scratches will not show, asin the case of paint or kalso- 
mine. For coloring sand finish, pulp stains of the best quality 
should be used; these are mixed with water to a thick cream and 
then thoroughly mixed with the finishing mortar, all the mortar for 
one room being mixed at one time to get it uniform. No plaster of 
Paris should be used in colored sand finish, as it will streak the wall. 
Dry colors, also, should not be used, as thev are quite sure to prove 
a failure. 


* These prices are about the average asked in the West. 


CHAPTER XII. 


CONCRETE BUILDING CONSTRUCTION. 


362. Concrete composed of broken stone, fragments of brick, pot- 
tery, gravel and sand, held together by being mixed with lime, 
cement, asphaltum or other binding substances, has been used in 
construction to resist compressive stress for many ages. 

The Romans used it more extensively than any other material, as 
the great masses of concrete, once the foundations of large temples, 
palaces and baths, the domes, arches and vaultings still existing, 
together with the core or interior portions of nearly all the ancient 
brick-faced walls found in Rome, testify. 

In the forest of Fontainbleau there are three miles of continuous 
arches, some of them fifty feet high, part of an aqueduct constructed 
of concrete and formed in a single structure without joint or seam. 
A Gothic church at Vezinet, near Paris, that has aspire 130 feet high, 
is a monolith of concrete. The lighthouse at Port Said is another, 
180 feet in height. 

The breakwaters at Port Said, Marseilles, Dover and other impor- 
tant ports, are formed of immense blocks of concrete. The water 
pipes and aqueduct at Nice,and the Paris sewers, are also notable 
modern constructions of the same material. 

In England and France thousands of dwellings have been built of 
concrete, in place of brick and stone. Many of these are now stand- 
ing, after more than half a century, without the least sign of decay. 
In the United States concrete buildings are comparatively few, the 
_ only notable building not of recent date being the large barn built 
at Chappaqua, N. Y., by Horace Greeley, more than thirty-five years 
ago, of an ordinary kind of concrete; this building has stood the test 
of exposure and is as good to-day as when built. 

The architects, engineers and capitalists of the United States ap- 
pear to have been the most timid of those of all civilized nations to 
avail themselves of the value of concrete as a building material, and 
it is only since the year 1885 that this material has been used to any 


358 BUILDING CONSTRUCTION. 


extent in the construction of buildings except for the purpose or foot: 
ings of foundation walls. 

Suitable materials for making concrete are available in almost 
every locality, and in most places solid walls of concrete are cheaper 
and more enduring than those of brick or stone. 

A concrete building needs no furring, as the walls are proof against 
dampness, and in a monolithic construction of concrete no possible 
danger to the structure can arise from fire within or without the 
building. 

While concrete in any form is not likely to take the place of stone, 
brick or terra cotta for architectural work to any great extent, yet the 
author believes that in combination with iron and steel it is destined 
to fill a large place in the construction of buildings, and that for 
warehouses, large stables, wine cellars, etc., it is the best and cheap- 
est material for producing substantial and incombustible work. The 
author also believes that in many localities cottages and larger dwell- 
ings could be advantageously built of concrete, and with a decided 
gain in durability and comfort. 

363. Notable Examples of Concrete Buildings.—Perhaps 
the best known of all concrete buildings in the United States are 
the hotels Ponce de Leon and Alcazar, at St. Augustine, Florida, 
Messrs. Carrere & Hastings, architects. 

These buildings, composed entirely of concrete, and exhibiting all 
the strains to which building material can be subjected, present an 
example of the almost limitless use to which concrete can be put. 

For the construction of these buildings an elevator was built at a 
central point of the operation, to the full height of the intended build- 
ing, and as the walls progressed, story upon story, runways were 
made to each floor, and the concrete, mixed by two capacious mixing 
machines on the ground level, was lifted in barrels and run off to the 


place of deposit. At times in the progress of the work 400 pounds of | 


cement were used in the concrete in a single day. 
The time transpiring between the wetting of the concrete and the 


\ 


| 


final running in place, even at the fifth story, was not more than ten | 


minutes at any time. 
The concrete was composed of 1 part imported Portland cement, 2 
parts sand and 3 parts coquina (a shell), the greater part passing 
through a $-inch mesh. 
The cost of the concrete in place was about $8 a yard, including 
arches, columns, etc. In plain thick walls the cost was often much 
less. 


CONCRETE BUILDING CONSTRUCTION. 359 


In the basement of the Alcazar is a bathing pool roo feet long, 60 
feet wide and 3 to ro feet deep, all made of concrete. Rising from 
this pool are concrete columns, 6 feet square at the base ard 40 feet 
high. These columns support concrete beams of 25 feet span, hol- 
lowed out in arch form, which support the glazed roof covering the 
interior court. 

364. The Leland Stanford, Jr., Museum, at Palo Alta, Cal- 
ifornia, a very large and costly building, is also constructed entirely 
of concrete. This building was built on the Ransome system—using 
twisted iron rods imbedded in the concrete to give tensile strength 
where required. 

The following description of this building, written by the architect, 
Mr. Geo. W. Percy, gives some idea of the method of construction 
and also of the cost. 


This building was designed to have dressed sandstone for the external walls, 
backed up with brick, and to have brick partitions with concrete floors. Owing to 
the great cost of stonework, it was decided to build the walls of cement concrete, 





Fig. 240. 


colored to match the sandstone used in the other university buildings, and to carry 
out the classic design first adopted. This led to making the entire structure walls, 
partitions, floors, roof and dome of concrete, making it, in that respect, a unique 
building. 

Having some knowledge of the disadvantages and defects natural to a mono- 
lithic building, such as result from the shrinkage and the expansion and contraction 
of walls, floor and roof, several new experiments were tried to overcome them, with 
varying results of success and failure. It was thought to overcome the cracking of 
walls by inserting sheets of felting through the walls, following the lines of the 
joints as near as practicable on each side of the windows. The lapping bond of the 
concrete, however, proved too strong to allow the cracking to follow these joints; 
in most cases the weakest points were found at the openings, and small cracks 
appear from window head to sills above. 


360 BOLLDINGAGCON SLA OGLTION. 


Joints were formed through the floors about 15 feet apart and in most cases the 
cracking has followed these joints and been confined tothem. To prevent the 
possibility of moisture penetrating through the walls, and also to render them less 
resonant, hollow spaces 5 inches in diameter were moulded in the walls within 2 
inches of the inside face, and with about 2 inches of concrete between them, 
These are successful for the primary object, and partially so for the secondary. 

The roof being the greatest innovation, and the first attempt known to the 
writer of forming a finished 
and exposed roof entirely in 
concrete, required the great- 
est care and consideration. 
The result in form and ap- 
pearance is shcwn by Fig. 
240, A and B, and may be 
described as follows: The 
roof is supported on iron 
trusses 10 feet on centre, 
and has a pitch of 20 de- 
grees. The horizontal con- 
crete beams rest on the iron 
rafters, and with the half 
arches form the horizontal 
lines of tiles about 2 feet 6 
inches wide, with the joints 
lapping 2 inches and a strip 
of lead inserted as shown. 
Vertical joints are made 
through the concrete over 
each rafter with small chan- 
nels on each side. These 
joints and channels are coy- 
ered with the covering tiles 
shown on drawings, and 
similar rows of covering 
tiles are placed 2 teet 6 
inches apart over the entire 





Fig. 241. roof, thus forming a perfect 

representation of flat Gre. 

cian tile or marble roof. Notwithstanding the precautions taken, this roof pre- 
sented several unexpected defects. The most serious proved to be in the Venetian 
red used for coloring matter and mixed with the cement. This material rendered 
the covering tiles absolutely worthless, many of them slacking like lumps of lime, 
and all were condemned and re-made. The same material injured the general sur- 
face of the roof, rendering it porous and necessitating painting. The roof over the 
central pavilion being hidden behind parapets, is made quite flat and covered with 
asphaltum and gravel over the concrete. This roof, with its low, flat dome, is 
without question the largest horizontal span in concrete to be found anywhere on 
earth, being 46 feet by 56 feet, the flat dome having all its ribs and rings of con- 


CONCRETE BUILDING CONSTRUCTION. 361 


crete, with the panels. or coffers filled with 1-inch thick glass and weighing about 
80,000 pounds.* 


This structure covers 21,000 feet and contains over 1,100,000 
cubic feet of space. It required about 260,000 cubic feet of con- 
crete, and was completed in seven months from the commencement 
of the foundations. 

The cost of the building per cubic foot, including marble stairs 
and wainscoting, cast iron window frames and sashes, and other parts 
to correspond, was about eighteen cents, which is a very low figure 
for a thoroughly substantial and fireproof building. 

Other important buildings which have been executed in concrete 
in the vicinity of San Francisco are the Girls’ Dormitory at the 
Stanford University (a three-story building completed in ninety days 
from the time the plans were ordered), the Science and Art build- 
ing, Mills College; the Torpedo Station on Goat Island, 80x250 feet, 
and an addition to the Borax Works at Alameda. In the latter the 
walls, interior columns and all floors are of concrete, and are remark- 
able for the lightness of the construction and great strength. 


All of these buildings were built on the Ransome system. 


365. The Alabama Hotel, Buffalo, N. Y.—The only large 
building constructed of concrete in the Eastern States in recent 
years that the author is acquainted with is the Alabama House, at 
Buffalo, N. Y., Mr. Carlton Strong, architect. This building is 
60x180 feet in size and six stories high, with all walls, floors and 
partitions built of concrete. 


The general plan of the wall and floor construction is shown by 
Fig. 242, which represents a. partial secticn at level-of third floor. 


The whole thickness of the wall is 24 inches from top to bottom, 
the inner portion being. 2 inches thick for the whole height; the 
outer portion is 8 inches thick in first story. and diminishes by 1 inch 
in each story. 


Vertical twisted rods are built in the walls, as shown in the figure, 
except that they are spaced about 15 feet apart lengthways of the 
wall. Opposite these vertical rods the withes are 3 inches thick, else- 
where 14 inches thick. In each withe are built } inch twisted rods, 


extending across the wall, and placed 12 inches apart vertically. At 
each floor level #-inch horizontal bars are imbedded in the walls 





* Fig. 241 shows an interior view of this dome and the hallway and corridors beneath. All 
the construction shown in this view is of concrete. In the first story the walls are cased with 
marble slabs, above they are firished with plaster. 


362 PULLING CON SLR UGCTION, 


as shown. ‘These twisted steel bars unite perfectly with the concrete 
and tie the walls together in all directions, while the shape of the 
wall gives the greatest stability with the least amount of material. I; 
will be noticed that the plan of this wall is very similar to that of the 
wall shown in Fig. 155. The concrete wall has this advantage over 
the brick wall, that moisture does not pass through the solid con- 















































Fig. 242. 


crete withes, while there is a possibility of its doing so in brick 
withes. The spaces in the wall are stopped at each floor level, 
except that for purposes of smoke flues or ventilation some of them 
are more or less continuous. 


The floors in this building are built on the Ransome system, of 
concrete with twisted rods. Most of the floors are of the paneled 
construction shown in Fig. 188 A, although some portions are flat, 
and of the type shown in Fig. 188. 


CONCKALZ LAO CILDING CONSTRUCTION. 363 


The partitions are also constructed of concrete, with twisted rods, 
and, being monolithic, add greatly to the stiffness of the building. 

Most of the concrete used in the construction of this building was 
made in the proportion of 1 part Portland cement to 6 parts aggre- 
gates. 

The contractors state that the average cost of the wall was twenty- 
five cents per square foot of outside surface. 

This building was commenced in 1894 and completed in 1896. 

366. Details of Construction.—The usual method of build- 
ing concrete walls, piers, arches, etc., is by setting up uprights of 4x4 
or 4x6 scantlings at each side of the proposed wall or pier and secur- 
ing to them boards or moulds, between which the concrete is depos- 
ited and rammed. To prevent springing the standards should be 
bolted together through the wall. For the moulding boards, dressed 
pine boards 14 inches thick are recommended; these should be 
brushed with a hot solution of soap each time before using. After 
the lower portion of the concrete has set the moulding boards may 
be removed and used above. 

Mr. Ernest Ransome, who has had much experience in the erec- 
tion of concrete buildings, has patented a movable cribbing, which 
consists of slotted standards, which, being placed in pairs, one on each 
side of the wall, and bolted together, hold in position the mould 
boards. These standards may be raised from time to time as the 
work progresses without interrupting the filling in of the concrete. 
In connection with the movable cribbing a series of hoisting buckets, 
with a traveling crane, is provided for hoisting the concrete. One 
man stationed upon the wall receives and empties the buckets of con- 
crete as they are hoisted and rams the concrete into place. The 
crane may be moved around the wall upon the upright slotted 
standards, so that no scaffolding whatever is required about the wall. 
It is claimed that the expense of working this apparatus need not 
exceed a cent per cubic foot of concrete. The first cost is also small. 

When mouldings are to be formed on the wall the reverse profile 
of the mould is stuck in wood and set in its proper place on the 
mould boards. 

Buildings of concrete may be erected very rapidly, as the process 
of depositing the concrete goes on continuously all around the build- 
ing, and there is no stone to cut or set, and with proper foresight 
there need be no waiting for materials. 

Concrete Beams or Lintels.—Wherever lintels or beams occur in con- 
crete buildings they should be formed of concrete and twisted rods 


354 BUILDING CONSTRUCTION. 


or cables in the manner shown in Fig. 243. A beam like that shown, 
22 inches wide and 2 feet 10 inches high, was used in a building in 
San Francisco, where it carries three stories of brick walls and wood 
floors, with a clear span of 15 feet. The twisted bars were 1 inch 
square. The three bars near the top were placed only over the sup- 
porting posts to give the effect of a continuous girder. 

367. Surface Finish.—Most of the concrete buildings con- 
structed previous to 1885 were finished on the outside with plas- 
ter or stucco in the manner described for plastering brick 
walls, Section 354. This finish has not proved very satisfactory, 
and, moreover, added considerably to the cost of the wall. This 
unsatisfactory surface finish 
undoubtedly has had much to 
do with the limited use of con- 
crete for wall construction. 

It has been demonstrated, 
however, that the natural face 
of the concrete can, at slight 
expense, be finished to closely 
imitate roughly dressed stone- 
work. Such imitation, more- 
over, is not, as in most cases, a 
false pretense or sham, as such 
surface finish is as natural to 
concrete as to. stone—concrete 
being in fact an artificial stone. 

The usual method of finish- 
ing the surface of concrete 
walls, when it is desired to 
imitate stonework, is by form- 
ing imitation joints in the face of the wall, and either picking or 
tooling the surface of the blocks thus formed, the former giving the 
appearance shown on the face of the wall, Fig. 242. 

The joints are formed by lightly nailing to the inside face of the 
moulding boards cleats or strips, moulded or beveled to give the 
desired form to the recessed joint. After nailing on the strips the 
inner face of the mould or cribbing will appear something like 
Fig. 244, the shape and size of the blocks varying to suit the char- 
acter of the work and the divisions of the wall. 

In imitating rough-dressed work the mould is taken from the con- 
crete while it is yet tender, and with small light picks the face of the 





CONGKEALTEL BOILDING CONSTRUCTION. 365 


stone is picked over with great rapidity, an ordinary workman 
finishing about 1,000 superficial feet per day. (The first and second 
stories of the Alabama House are finished in this way.) 

For imitations of finer-tooled work the concrete should be left to 
harden longer before being spalled or cut, and the work should be 
done with a chisel. ; 

A very neat effect may be obtained by chiseling a margin around 
the blocks to imitate tooled work, and then picking the centre, as 
shown in Fig. 245. 

If the strips are properly planed and beveled the recessed joints will need no 


‘‘touching up.”” Most natural stones (especially granite), bricks and clinkers, if 


crushed sufficiently fine, make excellent material for this face, but ordinary gravel 
will do. 















iS 


| 






NA ores 


\ 


1 
\ 
TN 


TJ 









\ 


\ 


\\ 







BY 
Nl 

















a 





Fig. 244. Fig. 245. 


\ 


MM 









he OFPSLT POR PLinTH 




















Whatever is used, let it be uniform in color and of anevengrade. Whenavery 
fine and close imitation of a natural stone is required, take the same stone, crush it, 
and mix it with cement, colored to correspond. 

The finer the stone is crushed the nearer the resemblance wiil be upon close 
inspection; but for fine work it is generally sufficient to reduce the stone to the 
size of buckshot or fine gravel. 

Rough effective work, excellent in appearance, can be obtained by using the 
ordinary concrete made with coarse materials. For a finer grade a better material 
should be used, with aggregates of coarse sand, very small gravel or finely-crushed 
stone. This fine grade need not extend through the mass of the concrete, but can be 
applied at the surface only, and by coloring in imitation of various natural stones, 
the most effective and pleasing results are obtained. 

The large bridge in Golden Gate Park, San Francisco, was made with coarse 
concrete, mixed 1 of cement, 2 of sand and 6 of quartzite rock taken out of adjacent 
hills and simply broken by hammers without screening, and notwithstanding its 
coarseness the structure has frequently been mistaken for natural stone by the 
public.* 


368. Making the Concrete.—JMaterials and Proportion.— 
Concrete for monolithic construction should be made of a good 





* Mr. E. L. Ransome. 


366 Bt LI ILIV G “COND La OCT IO Ns 


quality of Portland cement, mixed with clean, sharp sand and a proper 
proportion of aggregates. As previously stated, almost any natural 
stone, when broken up, ordinary gravel, or even broken bricks or 
pottery, may be used for the aggregates. Quartzite rock and granite 
make the best concrete, but the other materials will answer. Shells 
were used for the aggregate in the Hotel Ponce de Leon. 

The proportions may vary from 1 to 4 to 1 to 8. The proportions 
used in the buildings mentioned are given in the description. 

Mixing.—F¥or small buildings the concrete may be mixed by hand, 
as described in Section 142, but if very much concrete is required, it 
will be found much more economical to mix it by a regular mixing 
machine. 

Concrete can also be much more thoroughly mixed in a machine 
properly constructed for the purpose than is possible by hand, and 
the strength of the concrete is increased in proportion. 

Relative Strength of Mill and Hand-Mixed Concrete-—The opin- 
ions of engineers regarding mill-mixed concrete vary considerably. 
Some claim that it is not so good as hand-mixed, while others would 
not think of using hand-mixed concrete except on very small work. 
This difference in opinion is undoubtedly due to the difference in 
the working of the mills used. With the better class of mills there 
can now be no doubt that turning the concrete many times greatly 
increases its strength. 

In a series of tests with one mill it was found that the same con- 
crete, which when hand-mixed gave a crushing strength of 25 tons 
per square foot when one month old, when turned in the mill 500 
times gave a crushing strength of over go tons when one week old. 

Another series of tests furnished the author by Mr. E. L. Ransome 
gave the following results: 


I part Portland cement, 1 Rosendale, 12 limestone... I, 2, 3, 4, 8 weeks. 
No.1, -Mixed* by hand very thoroughly... >< -..<... 2.304 -——) 362.5408 05 
No. 2. Mixed in mill and turned 500 times......... 54, O13; ,Q0)) OO-n 117 


There is probably no doubt that in this country, at least, sufficient 
attention has not been given to the thorough mixing of the concrete, 
most architects and engineers placing more stress upon the question 
of tamping than upon that of mixing, whereas the latter is by far the 
more important of the two. 

Some years ago Mr. John Grant, the engineer of the Metropolitan 
Drainage Canal system of London, demonstrated that the advantage 
gained by tamping over the untamped concrete did not exceed 4a 
per cent. Within the past five years Mr. E. L. Ransome has dem- 


CONCRETE BUILDING CONSTRUCTION. 367 


onstrated that the best mill-mixed concrete and the best hand-mixed 
concrete vary Over 100 per cent. in strength. By means of mill mix- 
ing, therefore, it is possible to obtain a better and stronger concrete 
with a smaller proportion of cement, and consequently at less cost. 

Inspection.— Concrete work of all kinds requires the most rigid 
inspection (see Section 85), as almost everything depends upon the 
quality of the cement and proper mixing. Unless thorough confidence 
can be placed in the honesty of the contractor to use the proportion 
of cement specified, it will be necessary to keep an inspector con- 
stantly on the ground to see that the full proportion of cement is 























Fig 246. 


used. The quality of the cement furnished should also be tested 
from time to time as the work progresses. 


369. Expansion and Contraction.—Concrete diminishes 
slightly in volume in setting in air, and in monolithic construction 
this contraction is sufficient to produce cracks throughout the walls 
and floors. Some method should always be employed, therefore, to 
allow for expansion and contraction and to make the cracks follow 
false joints inthe work. One method adopted for accomplishing this 
result in walls is shown by Fig. 246. Through joints are formed at 
intervals by means of an iron plate, shown at / and on the plan. 
This plate is pulled up as the wall increases in height, leaving an 
open joint through the wall. Wherever these joints occur, recesses 


368 BUILDING CONSTRUCTION. 


are left in every alternate course, as shown at 4 A. These recesses 
are afterward filled with concrete blocks, formed separately and set 
in mortar like a stone. If the concrete contracts or settles the break 
will take place in the joints thus formed, and will not show on the 
face of the wall. 

Window sills should also be put in as slip sills, so that any settle- 
ment in the wall will not crack the ends of the sills. If the wall is 
jointed on the surface, as shown in Figs. 242 or 245, the window 
heads should be made in the form of a flat arch and a recess left for 
the key, which should be put in afterward. It is also advisable to 
have a through joint over the centres of all windows. 

When first attempting a concrete building, the architect will do 
well to consult with some person who has had experience with con- 
crete building as to the best arrangement of overcoming the effects 
of contraction and expansion. 

Concrete walls, with iron ties imbedded, when cracked, however, 
are notin the bad condition of stone or brick walls without such 
bond, as the iron ties may be depended upon to prevent spreading or 
falling. | 

370. Fireproof Vaults.—One of the rooms in the Leland Stan- 
ford, Jr.. Museum was designed to be the receptacle of many valu- 
ables, and to render it burglar-proof, the floor, walls and ceiling had 
copper wires imbedded in the concrete not over 3 inches apart, form- 
ing a continuous circuit, and designed to strike an alarm bell at the 
University if-any wire should be cut. : 

This device has also been in use in the U. S. Sub-Treasury in San 
Francisco for several years; it would seem to be very effective for 
prison walls and cells. 

Even without this electrical safeguard, concrete vaults may be 
made so as to resist the attempt of burglars for a long time and at a 
comparatively slight expense. 

Iron rods, old iron or steel, may be imbedded in the walls, floor 
and ceiling to as great an extent as may be deemed necessary ; these, 
being firmly held by the concrete, will be very difficult to cut or 
remove. Such vaults would also be thoroughly fireproo:, and, if 
made of sufficient thickness, would keep their contents unharmed, 
even should the building be completely destroyed. | 

“On one occasion, while building a concrete bank vault in an 
interior town, several tons of worn-out plowshares were placed in 
the concrete in such positions as would be most likely to discourage 
burglars in attempting to cut through the wall.” * 





* Mr. G. W. Percy, in Buclding 


CONCRALE BUILDING CONSTRUCTION. 369 


371. Sidewalk Construction.—For constructing sidewalks 
over areas or vaults, concrete may, in most localities, be used to bet- 
ter advantage as regards quality and economy than any other mate- 
rial or form of construction, as the concrete not only furnishes the 
necessary strength, but also the finished walk. 

Fig. 247 shows a section of monolithic sidewalk construction 
designed to obtain the maximum benefit from the glass discs built in 
the walk. No iron whatever is used in the construction of this walk, 
except for the twisted bazs and the columns supporting the beam A. 
As such sidewalks are usually constructed a beam is placed under . 
the wall to support the inner edge of t'.e walk. This beam naturally 
obstructs much of the light dispers . by the glass discs. In the con- 
struction shown the weight of the sidewalk is supported entirely by 





SECTION ON LINE XY. 
Fig. 247. 


the area wall, the beam 4 and the columns beneath. The beams B& 
are made to act as cantilevers, 41-inch twisted bars being imbedded in 
the top of the beams and crossways between the lights. The bars in 
the top of beams JZ are carried 5 or 6 feet beyond the beam 4, and 
the beams Z are placed opposite those marked C. The beams 4 
and C have # or 1 inch bars imbedded near the bottom to furnish 
the tensile strength. 

If necessary, the columns may also be dispensed with by putting 
trimmer beams opposite the piers to support the beam 4. | 

Other Uses for Concrete Construction.—There are vari- 
ous other uses which might be advantageously made of concrete con- 
struction, such as foundation and area walls, retaining walls and area 
steps. 

When the foundation walls start from different levels Portland 
cement concrete may be used with especial advantage, as it is sub- 
ject to but very little, if any, settlement or compression, and conse- 
quently if the settlement of the ground is uniform no cracks will ap- 
pear in tne walls. 


3694 BUILDING CONSTRUCTION. 


it is also claimed that concrete gives a drier basement than stone 
or brick, and in many localities it should be cheaper. The walls 
should be built in the manner described in Section 366, using plain 
boards for the moulds. 

For retaining walls concrete-iron construction would appear to be 
eminently adapted, as there is always a tendency in such walls for 
the joints to open at the back, or for the upper part to slide on the 
lower. Both of these tendencies are readily overcome by using Port- 
land cement concrete and twisted iron, and the wall need only be 
made of such thickness that it cannot be overturned bodily. 

Concrete is also well adapted, in many localities, for steps to areas, 
or in terraced grounds to ascend from one level to another. Such 
steps are generally more exposed to moisture and dampness, and dis- 
integrate more quickly, if of stone, than in almost any other situa- 
Saree tion. With concrete steps the 
4° Bar Twisted {ne ‘ dampness simply increases their 

aN strength and hardness. 
af Where the ground is firm con- 
crete steps may be built by shap- 
ing the ground, then setting up a 
cat) form for the risers, and filling in 
ae the concrete between the form and 
hy ie the ground, the treads being 
smoothed off with a trowel. By placing #-inch twisted bars in the 
angles, as shown in Fig. 248, these steps may be made fully as pHERE 
as if built of stone, and more durable. 

The thickness of the concrete should be from 2 to 3 inches. On 
doubtful ground. or any ground that is subject to frost, +-inch twisted 
bars should be bent to the shape of the steps and hav in the con- 
crete, as shown in the figure, to prevent the treads and risers 
being broken by settlement or heaving of the ground. These smaller 
bars may be placed from 1 to 4 feet apart, according to the nature 
of the soil. 

Where the ground is not sufficiently firm to sustain the concrete 
without assistance, a thin sheet of iron may be set up to hold the 
back of the riser, as shown by the heavy line, and after the concrete 
riser has been formed the iron can be withdrawn, the earth tamped 
slightly, and the same iron used for the next step, and so on, step by 
step. 

Test of Concrete Slabs Built on the Ransome Sys< 
tem.—The following tests of the transverse and shearing strength 





CONCRETE BUILDING CONSTRUCTION. 3696 


and the resistance to impact of a concrete slab 4 inches thick were 
made by Prof. Miller, Chief of the Engineering Laboratory of the 
Massachusetts Institute of Technology, early in 1896: 

The-slab was 5 feet wide, 14 feet long and 4 inchés thick, with 
3-inch twisted steel bars 6 inches on centres imbedded near the bot- 
tom. ‘The concrete was made of 1 part Alsen cement, 1 part sand 
and 6 parts broken stone (2 parts passing through a $-inch ring and 
4 parts through a }-inch ring). 

The slab was laid over the tops of four steel I-beams, spaced 4 
feet 8 inches apart on centres, thus making a continuous beam of 
three equal spans. Over the supports ;%;-inch twisted burs, 3 feet 
long, were imbedded in the top of the concrete. 

The first section was tested by building a brick pier over tts entiré 
area until a load of 724 pounds per square foot was attained, when 
the deflection was 5 inch, without cracking. On the middle span a 
spruce beam, 8x12 inches and 8 feet 4 inches long, weighing 164% 
pounds, was dropped five times from a height of 7 feet 10 inches, 
twice striking in the same spot, without doing any damage. 

By means of screw jacks a pressure of 6,200 pounds was applied 
on an area of about $xg inches between two twisted bars without 
breaking; on increasing the pressure the concrete cracked and failed. 
Finally a steel beam was laid across the centre of the middle span 
and a load of 20,700 pounds put on by a jack screw before the con- 
crete cracked, the deflection reaching 145 inch. 

ADDENDA TO FIFTH EDITION. 

Since this chapter was written, Concrete Construction has had a notable extention 
for all kinds of work. 

The extent to which the Ransome system, alone, has been used in the construction 
of buildings and factories, is only partially indicated by the following list of build- 
ings, having walls, floors and partitions of concrete. 

Fifteen Story Office Building, Washington, D. C. 

St. James Church, Brooklyn, N. Y. 

Willard Parker Hospital, New York City. 

Court House and Jail, Mineola, Long Island. 

Grand Stand, Cincinnati, Ohio. 

Six dry kilns and two factories for Singer M’f’g Co., Cairo, Il. 

Twenty four dry kilns, pattern house and oil house, South Bend, Ind. 

Four story Refinery for Pacific Coast Borax Co., Bayonne, N. J. 

Factory for the Farley Duplex Magnet Co., Jersey City, N. J. 

Factory for the Central Lard Co., Jersey City, N. J. 

Warehouse for the Pacific Coast Borax Co, Bayonne, N. J. 

Two 130 ft. Chimney stacks at South Bend, Ind., and one 100 ft. stack at Jersey 
City. 

The Ransome & Smith Co. give the cost of Factory buildings under their system 
at 7 cents per cubic foot. 


CHAPTER XIII. 
SPECIFICATIONS. 


372. The specifications for any particular piece of work should 
be considered as of equal importance with the drawings. The archi- 
tect should not expect the contractor to do anything not provided 
for by the plans and specifications without extra compensation, nor 
to do the work better than the specifications call for. He must 
therefore be sure that everything which he wishes done is clearly 
indicated either by the plans or specifications, and that no loopholes 
are allowed for poor workmanship or inferior materials. ‘The por- 
tions of the work to be done by each contractor should also be clearly 
stated, so that there can be no misunderstanding as to who is to do 
certain portions of the work. It very often happens that some minor 
details, such as closing up the windows, protecting stonework, etc., 
are not properly specified, and the contractors dispute, much to the 
annoyance of the architect, as to who shall do that part of the work. 
Such annoyances are largely avoided when the entire contract for the 
erection and completion of the building is given to one person or 
firm, but even then it is better to have the duties of the sub-contract- 
ors clearly defined. 

As a rule, the form, dimensions and quantity of all materials 
should be fully indicated on the drawings, so that only the kind and 
quality of the materials and the manner of doing the work need be 
given in the specifications. General clauses should be avoided as far 
as possible, as they only cumber the specifications and tend to 
obscure the really important portions. 

The following forms of specifications for various kinds of mason 
work are given merely as a guide or reminder to architects, and not 
always to be copied literally. Figures or words enclosed in ( ) may 
be changed to suit special or local conditions. | 

Every specification should be prepared with special reference to 
the particular building for which it is intended. 

The use of standard specifications is not recommended, as when 
such specifications are used the architect is more apt to overlook 
important points, and the use of such forms, moreover, tends to a 
lack of progressiveness and a study of the best construction to suit 
the varying circumstances of different buildings. 


SPECIFICATIONS. 371 


The author would recommend to the young architect that before 
commencing to write or dictate his specifications he make a skeleton, 
consisting of headings of the different items to be specified, carefully 
looking over the plans and revising the skeleton until everything 
seems to be covered and, the headings arranged in their proper 
sequence. ‘The specifications can then be filled out in the manner 
herein indicated. | 

GENERAL CONDITIONS. 


373. Every specification should be preceded by the general con- 
ditions governing all contractors. ‘These may advantageously be 
printed on a separate sheet and used as a cover to the written speci- 
fication, and should not be repeated in the latter. 

The general conditions used by different architects vary more or 
less, according to the experience of the architect. 

The following form has been used by the author for a number ot 
years with satisfactory results : 


General Conditions :—The contractor is to give his personal superintendence 
and direction to the work, keeping, also, a competent foreman constantly on the 
ground. He is to provide all labor. transportation, materials, apparatus, scaffold- 
ing and utensils necessary for the complete and substantial execution of everything 
described, shown or reasonably implied in the drawings and specifications. 

All material and workmanship to be of the best quality throughout. 

The contractor must carefully lay out his work and be responsible for any mis- 
takes he may make, and any injury to others resulting from them. 

Where no figures oy memoranda are given, the drawings shall be accurately fut- 
lowed according to their scale; but figures or memoranda are to be preferred. co 
the scale in all cases of difference. 

in any and all cases of discrepancy in figures, the matter shall be immediately 
submitted to the architects for their decision, and without such decision said dis- 
crepancy shall not be adjusted by the contractor save and only at his own risk ; 
and in the settlement of any complications arising from such adjustment, the con- 
tractor shall bear all the extra expenses involved. 

The plans and these specifications are to be considered co-operative ; and all 
works necessary to the completion of the design, drawn on plans, and not descriled 
herein, and all works described herein and not drawn on plans, are to be consid- 
ered a pcrtion of the contract, and must be executed in a thorough manner, with the 
best of materials, the same as if fully specified. 

The architects will supply full-size drawings of all details, and any work con- 
structed without such drawings, or not in accordance with them, must be taken 
down and replaced at the contractor’s expense, ; 

Any material delivered or work erected not in accordance with the plans and 
these specifications must be removed at the contractor’s expense and replaced with 
other material or work, satisfactory to the architects, at any time during the pro- 
gress of the work. Or in case the nature of the defects shall be such that it is not 


372 DOLLDING CONSTAKOCTION, 


expedient to have it corrected, the architects shall have the right to deduct such 
sums of money as he considers a proper equivalent for the difference in the value 
of the materials or work from that specified, or the damage to the building, from 
the amount due the contractor on the final settlement of the accounts. 

The contractor will provide proper and sufficient safeguards and protection 
against the occurrence of any accidents, injuries, damages or hurt to any person or 
property during the progress of the work, and shall be alone responsible, and not 
the owner or the architects, who will not in any manner be answerable for any loss 
or damage that may happen to the work, or any part thereof, or for any of the 
materials or tools used and employed in finishing and completing the work. 

The contractor must produce, when called upon by the architects, vouchers from 
the sub-contractors to show that the work is being paid for as,it proceeds. 

Every facility must be given the architects for inspecting the building in safety, 
such as ladders, scaffolding and gangways, and provision to be made to the archi- 
tects’ satisfaction for protection from falling materials. 

The drawings are the property of the architects and must be returned to them 
before the final payment is made. 

The contractor is to keep the building at all times free from rubbish and shav- 
ings, and on completon to remove all rubbish and waste material caused by any oper- 
ations under his charge, clean up the house and grounds, and leave the wor" per- 
fect in every respect. 


EXCAVATING AND GRADING. 


374.— Tne contractor shall visit the site of the building and examine for him- 
self the condition of the lot, and satisfy himself as to the nature of the soil. 


[Where this is not practicable the architect should show the pres- 
ent grade of lot by red lines on the elevation drawings, and the 
nature of the soils should be determined by borings or test pits. See 
Section 4. | 

Loam.—This contractor is to remove the present top soil to the depth of 12 inches 
frcm the site of the building and for (20) feet on each side, and stack where indi- 
cated on the lot. 

Excavate to the depth shown by the drawings for the cellar, areas, coal vault 
and outside entrance, and for trenches under all walls and piers. All trenches 
shall be excavated to the neat size as far as practicable, and each shall be leveled 
to a line on the bottom, ready to receive the foundation. This contractor must be 
careful not to excavate the trenches below the depth shown by che drawings; 
should he do so he must pay the mascn for the extra mason work thereby made 
necessary, as under no condition will dirt filling be allowed. 

All excavations to be kept at least (12) inches outside the outer face of walls. 
(See Section 31.) 


[Excavations for drains, dry wells, furnace pit, air ducts, €tceato 
be specified here if required. | 


Water.—Should water be encountered in making the excavations, this con- 


tractor is to keep it pumped out of the way until the footings are set, unless practi- 
cable to drain into sewer. 


SPECIFICATIONS. S¥is) 


Stome.—Should a solid ledge be encountered in the excavations, this contractor 
is to remove the same by blasting or other process, and is to pile the stone where 
directed on the lot (if suitable for foundation). For removing such stonework an 
extra sum of ( cents) per cubic foot of stone excavation will be paid, but no 
extra payment will be made for removing boulders or loose stones. 

Remove from the premises as soon as excavated all material except the loam 
and such as may be needed for filling about the walls (or grading). 

filling.—When directed by the architect, this contractor shall fill about the 
walls (with stone, gravel or sand) to within (3) feet (half their height) of the fin- 
ished grade, and as soon as the first floor joist are set he shall complete the filling 
to the grade line, tamping the earth solidly every 6 inches. (See Section 87.) 

Gi ading.—Grade the surface of the lot to the level indicated by the drawings 
(using the loam first removed) and leave in good condition for top dressing (or pav- 
ing.) (Foundations for walks and driveways.) 





| When building on a site formerly occupied by a building, or cov- 
ered with rubbish, the specifications should provide for the removal 
of all rubbish, debris, old foundation stone, sidewalk stone and other 
materials that cannot be used in the new building. | 


FILING. 


375-—This contractor is to furnish and drive the piles indicated on sheet (1). 

All piles shall be of sound (white oak, yellow pine, Norway pine or spruce), 
They must be at least (6) inches in diameter at the head and (10) inches at the butt 
when sawn off, and must be perfectly straight and trimmed close and have the 
bark stripped off before they are driven.* 

The piles must be driven into hard bottom or until they do not move more than 
4 inch under the blow of a hammer weighing (2,000) pounds, falling (25) feet at the 
last blow. They must be driven vertically and at the distances apart required by 
the plans. 

They must be cut off square at the head, and, when necessary to prevent broom- 
ing, shall be bound with iron hoops. 

All piles, when driven to the required depth, shall be cut off square and hori- 
zontal at the grade indicated on the drawings by this contractor. 

(See Sections 35, 36 and 37.) 


CONCRETE FOOTINGS. 


376.—All footings colored (purple) on the foundation plan and sections shall 
be constructed of concrete furnished and put in place by this contractor. 

W the trenches are not excavated to the neat size of the footings, or where the con- 
crete is above the level of cellar floor, fhis contractor shall set up 2-inch plank, sup- 
ported by stakes or solidly banked with earth to confine the concrete, and these planks 
are not to be removed until the concrete is (48) hours old. 

The concrete shall be composed of first-quality fresh (Atlas) cement, clean, sharp 
sand and clean (granite) broken to a size that will pass through a 23-inch ring, and 
thoroughly screened. These ingredients shall be used in the proportion of I part 





* This latter clause is not always required. 


374 BOULLDINGSCONS TF OGL LOIN: 


cement, 2 of sand and 4 of stone, and mixed each time by careful measurement, in 
the following manner: Ona tight platform of plank spread four barrows of sand, 
and upon this two barrows of cement. Thoroughly mix the two dry, and then throw 
on eight barrows of broken stone and work over again; then work thoroughly and 
rapidly with shovels while water is being turned on with a hose, until each stone is 
completely covered with mortar. No more water to be used thah is necessary to 
unite the materials. As soon as the concrete is mixed it is to be taken to the trenches 
and dumped in layers about 6 inches thick, and immediately rammed until the water 
flushes to the top. The next layer must be put on before the preceding one becomes 
dry, and the top be well wet before putting in the new layer. The stone footings shall 
not be put on the concrete until it is two days’ old. (See Sections 140, 145.) 


[On large and important work the specifications should also pro- 
vide for testing the cement. (See Section 125.) The above quanti- 
ties are as much as should be mixed at one time. | 


SPECIFICATIONS FOR STONEWORK. 


377.—Footings.— Supported on Piles.—The pile capping to be of even split 
granite blocks (16) inches thick from quarries, to be of such size that no 
stone will rest on move than three piles, and to be bonded as shown on special draw- 
ing. Each and every stone is to be carefully wedged up with oak wedges on the 
head of each pile to secure a firm and equal bearing, and are to butt closely together. 





Dimension Footings. —The footings under all outside foundation walls are to con- 
sist of dimension stone from the 





(ony c 





quarries, of the width shown on 
the section drawings and (12) inches thick. To have fair surfaces top and bottom, 
and to be bedded and puddled in cement mortar. No footing stone to be less than 
(3) feet long. 


Rubble Footings.—Build the footings under (all other) foundation walls of the 
width and thickness shown by section drawings, of stone. The stone to be 
heavy rubble, each stone to be of the full thickness of the footing course, at least 2 
feet 6 inches long, and not more than two stones abreast in the width of the wall; 
there shall also be one through stone, the full width of the footings, every (6) lineal 
feet. Each stone is to be solidly bedded and puddled in cement mortar, and all 
chinks between the stones are to be filled solid with mortar and spalls. 





378.—Foundation Walls.—Block Granite or Limestone.—Build the founda- 
tion walls colored (blue) on plans to the height and thickness shown by section draw- 
ings, of sound, even, split granite (limestone) blocks to average (3) feet in length, (18) 
inches wide and to be not less than (12) inches in height. To be laid with a good 
bond in regular courses, as near as can be, and bonded with one through stone in 
every (10) square feet of wall 

The stone to be laid in cement mortar, as described elsewhere, all chinks and 
voids to be filled with slate or (granite) spalls and mortar, to show a good straight face 
where exposed in the basement, and the joints to be neatly pointed with the trowel. 
_All walls must be built to a line both inside and outside, and all angles to be plumb. 
(Inside face of wall to be hammer-dressed.) Top of wall to be carefully leveled for 
the superstructure, with heavy stones at each corner. Leave holes in wall for drain, 
gas and water pipes. 


SPECIFICATIONS. A bs, 


Rubble Watlls.—Build the foundation and basement walls colored (gray) on plans 
to the height and thickness shown on section drawings, of stone rubble. To 
be of selected, large size, first quality stone, laid to the lines on both sides, well fitted 
together, and all voids filled solid with spalls and mortar. Each stone to be firmly 
bedded and cushioned into place, and all joints shall be filled with mortar. At least 
half of the stones are to be two-thirds the width of the wall, and there shall be one 
through stone to every (10) square feet of wall. The larger part of the stones shall 
be not less than (2 feet) long, (16 inches) wide and (8 inches) thick. The wall to be 
laid in courses about (18 inches) high and leveled off at each course.* (Each stone 
shall have hammer-dressed beds and joints, and the face of the stone showing on the 
inside of the wall shall be coarse bush-hammered.}) The wall to be built plumb and 
carefully leveled on top to receive the superstructure. 





Cementing Outside of Wall.—As soon as the wall is completed the contractor is 
to rake out all loose mortar in the outside joints and plaster the entire outside of the 
wall (except where exposed in areas) with Dyckerhoff Portland cement mortar not less 
than 4 inch thick. The mortar to be mixed in the proportion of 1 tor. Area walls 
to have the joints raked out and pointed with cement mortar, anda false joint of red 
cement mortar run with a jointer and straight-edge. The trench is not to be refilled 
until the wall has been plastered at least twenty-four hours. 

Basement Piers.—All piers colored (blue) on basement plan to be built of 
stone, and each stone shall be of the full size of the pier ¢ laid on its natural bed, and 
the top and bottom of each stone to be cut so as to form joints not exceeding } inch 
in width. All four sides of pier to be rough pointed and all corners to be pitched 
off toaline. The top stone to be dressed to receive the iron plate resting on the pier 
and each stone to be solidly bedded in cement mortar as specified elsewhere. 

Mortar.—All stone masonry above referred to shall be laid in mortar composed of 
perfectly fresh (Rosendale) cement, 








brand, mixed in the proportion of 1 part 
cement to (2) parts of clean, sharp sand. The sand and cement shall be mixed dry 
in a box, then wet, tempered and immediately used. (See Section 128.) No mortar 
that has commenced to set to be used on the work. 


379.— External Stone Walls.—Awéd/e.—Build the external walls (in first 
story) of rubble from the quarries. To be laid. random, with hammer- 
dressed joints, and the outside face split so that the projection shall not exceed 2 
inches. The stones to be laid on their natural bed, with. good vertical bond, and to 
be one through stone in every 10 square feet of wall. All stones showing on the 
exterior to be selected from the largest in the pile, and as few spalls to be used as 
possible. Every stone to be well bedded in mortar, made of I part (Rosendale) 
cement and (2) parts clean, sharp sand, and all joints and chinks filled solid with mor- 
tar and spalls. All inside joints to be smoothly pointed with the trowel as the wall 
_ is built. After the wall is built the joints on the outside are to be raked out and 
filled with cement mortar, and a false joint of red Portland cement mortar run with 
a jointer and straight-edge, in imitation of broken ashlar. 








* This is unnecessary in ordinary foundations for dwellings. 


+ Only required in places where a neat and extra strong wall is required. This is expensive 
work. 


+ Or, in courses varying from 8 to 12 inches in height, every other course to be the full size of 
the pier and the intermediate course to consist of two stones, each one-half the size of the pier. 
Each stone to be laid on its natural hed, etc. 


376 BUILDING CON SLA OCLTION. 


Field Rubble.—The external wall of (first story) is to be faced with round field 
stones, selected for their color, and the moss and lichens left on. The stones to be 
fitted together according to their size and without spalls. The back and sides to be 
split with the hammer where necessary to give a bond, and the stones to have their 
long axis crossways of the wall and to be laid in cement mortar. The wall to be 
backed up with split-face rubble carefully bonded to the facing. 


CUT STONEWORK. 


380.—Granite.—All trimmings colored blue on the elevation drawings to be of 
(Quincy) granite. The stock to be carefully selected and free from all natural imper- 
fections, such as mineral stains, sap or other discolorations ; to be of an even shade 
of color throughout, so that one stone shall not look of a different shade from another 
when set in place. 

The face of sills, caps, quoins and water table. where so indicated on the elevation 
drawings, to be pitched face, with 1-inch angle margin on the quoins and water 
table. All steps and thresholds to be hammered work, six-cut, and the balance of 
the trimmings to be best eight-cut work. 

Sandstone.—All trimmings shown by brown color on the elevation drawings to be 
of best quality selected (Cleveland) buff sandstone, of uniform color and hardness, 
free from sand holes and rust, and cut so as to lay on its natural bed when set in the 
wall. All stone trimmings thus shown are to be worked in strict accordance with 
the detail drawings, with true surfaces and good sharp, straight lines; and all stone 
belts, unless otherwise provided for, are to have a bearing upon the walls of at least 
(6) inches, and the projecting courses to have a bearing of 2 inches more than the pro- 
jection. All exposed surfaces of the sandstone are to be carefully tooled, (rubbed) 
or (crandalled), the workmanship being regular and uniform in every part and done 
in a skillful manner. All mouldings to be carefully fitted together at the joints, and 
no horizontal or vertical joint to exceed 33; of an inch. Allreturn heads at the angles, 
etc., are to be at least (12) inches. No patching of any stone will be allowed. 


[Ordinary soft sandstones, or “freestones,” are not suitable for 
steps and door sills, which should be either of granite or some hard 
sand or limestone. | 


A shlar.—The (south) and (west) walls of the building where exposed above the 
(water table) are to be faced with coursed (broken) ashlar of the same stone as specified 
for the trimmings. The ashlar to be in courses (12) inches high, except as otherwise 
shown on elevation drawings, and to have plumb bond wherever practicable. (The sur- 
face of the quoins to be raised 1 inch from the face of the wall, with beveled or rusticated 
joints, and the faces of the stones to be rusticated in a skillful manner. Each quoin 
to be (16)x(24) inches, reversed as shown on drawings.) The balance of the ashlar 
to be rubbed to a true surface, without wind, cut to lie upon its natural bed, and for 
ys-inch joints. No stone to be less than 4 inches thick, and at least one jamb stone 
to each opening to extend through the wall. All mullions 16 inches or less in width 
to be cut the full thickness of the wall. 

The contractors, both for the granite and sandstone, are to do all drilling, lewising, 
fitting and other jobbing required for setting the stone or to receive iron ties, clamps, 
etc., and are to provide all patterns necessary and required for the execution of the 
work. 


SPECIFICATIONS. 377 


Setting Stonework.—[The specifications should distinctly state who 
is to set the stonework. If the stonework consists of a few trim- 
mings only it will be cheaper for the brick mason to set it, but if there 
is much stonework it should be set by the stone mason. | 


All stonework shown by blue or brown color on the elevation drawings, and as 
previously specified, is to be set in the best manner by this contractor in mortar mixed 
in the proportions of 2 parts of (Rockland) lime mortar and 1 part fresh (Rosendale) 
cement. The cement to be mixed with the lime mortar in small quantities and in no 
case shall any be used that has stood over night. (lor setting limestone and marble 
see Section 208.) 

As the stone is delivered at the building the mason will accept the same and be 
held responsible therefor until the full completion of his contract; any damage 
that may occur to any stone, whether on the ground or in the building, during the 
said period, shall be made good at his own expense and to the satisfaction of the 
architect or superintendent. 

The mason must call upon the carpenter to box or otherwise protect by boards all 
steps, mouldings, sills, carving and any other work liable to be injured during the 
construction of the building. ; 

Every stone to be carefully set, joints left open under centre of sills and at the outer 
edges of all stonework, and all stones to be uniformly bedded, joints kept level and 
plumb and of uniform thickness. The mason is to provide derricks and all other 
apparatus necessary to set the stone properly, and is to carry on the work so as not to 
delay the other mechanics. Where the stone is backed up with brick the stone shall 
not be set more than two courses ahead of the backing. 

Anchors and Clamps.—This contractor is to provide all necessary iron anchors and 
clamps (which are to be galvanized or dipped in tar) for securing the stone as herein 
specified or as directed by the superintendent. 

Each piece of ashlar 12 inches or more in height is to have one iron anchor 
extending through the wall, and when exceeding 4 feet in length two clamps are to 
beused. (Broken ashlar will be bonded by through stones, one to every I0 square feet 
of wall.) Also anchor all projecting stones, corbels, finials, etc., with iron anchors 
satisfactory to the superintendent. AlJl coping stones and other horizontal string 
courses or cornices, where so indicated by notes on the drawings, are to be clamped 
together. | 

Cleaning and Pointiny.—After all the stonework is set complete (and the roof is 
on) the mason shall scrub down with muriatic acid and water, using a stiff bristle 
brush, all stonework, rake out all joints to the depth of I inch and repoint with Port- 
land cement and (Clinton) red, well driven into the joint and rubbed smooth with 
the jointer with half round raised joint as per marginal sketch. (It will be well to 
show in margin the kind of joint desired; see also Section 2009). 

The entire work to be left clean and perfect on completion of the contract. 


SPECIFICATIONS FOR BRICKWORK. 


381.—This contractor is to furnish all materials, including water, and all 
labor, scaffolding and utensils necessary to complete the brickwork indicated. by 
red color on the plans and sections, and as shown by the elevations and as herein 
specified. 


378 BUILDING CONSTRUCTION. 


Face Work.—Pressed Brick.—The exposed surfaces of the building (on south 
and east elevations), including the chimneys, to be faced with (St. Louis) pressed 
brick like the sample in architect’s office ; all to have good sharp edges and to be of 
uniform size and color. 


Moulded Brick.—Furnish all moulded brick shown on elevation drawings and 
as indicated by numbers (which refer to ’s catalogue). These brick to be as 
near the color of the pressed brick as can be obtained, and laid to give as even lines 
as possible Furnish octagon brick for the external angles of bays and circular 
brick of proper curvature for the circular bay (or tower). 





Stock Brick.—The exposed surfaces of the brickwork (on west elevation) to be 
of best quality dark red stock brick, with good sharp corners and square edges. 


Common Brick.—The balance of the exposed brickwork to be of selected, even- 
colored common brick, as nearly uniform in size and color as can be obtained, and 
carefully culled. 

All face brick to be laid in the most skillful manner (from an outside scaffold) 
in colored mortar, as specified elsewhere. Each brick to be dipped in water before 
laying; each edge of the brick and down the middle to be butted, and all 
vertical joints to be filled solid from front to back. The brick to be laid with 
plumb bond and bonded to the backing with a diagonal header to every brick in 
every (fifth) course. [Or bonded with the Morse tie, one tie laid over every brick 
in every fourth course.] In piers only solid headers to be used. 

All courses to be gauged true, and all joints to be rodded (or struck with a bead 
jointer. See Section 237). 

The returns of pressed brickwork must be carefully dovetailed into the common 
brickwork or bonded by solid headers. 


Ornamental Work,—All brick cornices, belt courses, arches, chimney tops and 
other ornamental brick features of the building must be laid up in the most artistic 
and substantial manner, according to the scale and detail drawings. All arches to 
be bonded and the bricks cut and rubbed so that each joint will radiate from the 
centre. (Arch brick are often specified for first-class work in large cities.) 


Common Brickwork.—All\ other brickwork to be laid up with good hard-burned 
(the best merchantable) common bricks, acceptable to the architect, in mortar, as 
specified elsewhere. 

All brick shall be well wet, except in freezing weather, before being laid. 

Each brick shall be laid with a shove joint in a full bed of mortar, all interstices 
being thoroughly filled, and where the brick comes in connection with anchors each 
one shall be brought home to do all the work possible. 

Up to and including the fourth story every fourth course shall consist of a head- 
ing course of whole brick, extending through the entire thickness of the wall or 
backing ; above the fourth story every sixth course shall be a heading course. 


All mortar joints, where the wall is not to be plastered, shall be neatly struck, 
as is customary for first-class trowel work. All courses of brickwork shall be kept 
level, and the-bonds shall be accurately preserved. When necessary to bring any 
courses to the required height, clipped courses shall be formed (or the bricks laid 
on edge), as in no case shall any mortar joints finish more than } inch thick. All 
brickwork shall be laid to the lines, and all walls and piers must be built plumb 
true and square. Walls to be carefully leveled for floor joist. 


ne Pos ritC aT LON'S, 379 


All cut stone shall be backed up as fast as the superintendent shall direct, and the 
brick mason shall build in all anchors that may be furnished by the contractor for 
the cut stonework, or by the carpenter or iron contractor. 

All partition walls to be tied to the outside walls byiron anchors (furnished by 
this contractor), ;3;x1} inches in section and (3 feet 6 inches) long, built into the 
walls every (4) feet in height. 

When openings or slots are indicated in the brick walls, tle size and position of 
the same shall be such as the superintendent shall direct, unless otherwise shown. 
This contractor shall leave openings to receive all registers that may be required in 
connection with the heating or ventilating system. 

Firmly bed and fill in around all timbers, point around all window frames, inside 
all staff beads and window sills, and wherever required, and bed all wall plates in 
mortar on the brickwork. 


Protection.—This contractor shall carefully protect his work by all necessary 
bracing, and by covering up all walls at night or in bad weather. (He shall protect 
all mason work from frosts by covering with manure or other materials satisfactory 
to the superintendent. 

The top of all walls injured by the weather shall be.taken down by this contractor 
at his expense before recommencing the work. 

Floliow Fire Clay Brick (for buildings of skeleton construction).—AII brick used in 
connection with the spandrels above the first story on all elevations, together with 
all backing required in connection with the stone or terra cotta work above the (sixth) 
story floor beams, shall consist of first quality hard-burned fire clay, hollow brick, 
equal in quality to sample in the architect’s office. Each brick shall be laid with a 
shove joint and the work well bonded. The inside surface of the wall to be left 
smooth, true and ready for plastering. 

Mortar.—Cement Mortar.—All brickwork below the grade line and the last five 
courses of chimneys and parapet walls shall be laid in mortar composed of I part 
fresh (Rosendale*) cement and (2) parts clean, sharp bank sand, properly screened, 
mixed with sufficient water to render the mixture of proper consistency. Care must 
be taken to thoroughly mix the sand and cement dry, in the proportions specified, 
before adding the water. The mortar shall be mixed in small quantities only, and 
in no case shall mortar that has commenced to set or stood over night be used. (See 
Section 128.) 


[In Colorado, and possibly in some other localities, a gray hydraulic. 
lime is obtained, which answers about as well as cement for founda- 
tion walls. | 


Lime and Cement Mortar.—All common brickwork in (first and second) stories 
to be laid in mortar composed of (3) parts of lime mortar, having a large proportion 
of sand and 1 part of fresh (Utica) cement. The lime mortar to be worked at least 
two days before the cement is added, and only small quantities of cement to be mixed 
at a time (see Section 131.) 

Lime Mortar.—The balance of the common brickwork to be laid in mortar com- 
posed of fresh-burned (Rockland) (Missouri) lime and clean, sharp sand, well 
screened. (No loam to be used.) The lime and sand to be mixed to make a rich 


* Or any of the cements described in Section rrr. 


380 BUILDING CONSTRUCTION. 


mortar, satisfactory to the architect. Lime that has commenced to slake shall not be 
used. 

Colored Mortar.—All face brick to be laid in mortar composed of lime putty and 
finely-sifted sand, colored with (Pecoria) or (Peerless) mortar stains; colors to be 
selected by the architect. 


Grouting.—All brick footings and the piers in basement must be grouted in every 
course and flushed full with cement mortar, as specified above. 


Cement Plastering.—The outside of all brick walls that come in contact with the 
earth shall be smooth plastered by this contractor, from bottom of footings to grade 
line, with (Atlas) Portland cement mortar, mixed in the proportion of I to 2, and of 
an average thickness of } inch. 

Plaster the top of all projecting brick belt courses, and the topsof fire walls, where 
not otherwise protected, with the same kind of mortar, being careful to make a neat 
job. (See Section 240.) 

Relieving Arches.—Turn three rowlock relieving arches over all door and win- 
dow openings behind the face arch or lintel. These arches to have a brick core, 
and to spring from beyond the ends of wood lintel. 


Chimneys.—Build all chimneys and vent flues as shown by drawings, and top out 
as shown on elevation drawings. 

All withes to be 4 inches thick, well bonded to the walls, and the flues to be car- 
ried up separately to the top. Plaster the inside of all flues (unless provided with 
flue lining) from bottom to top with (Portland cement) mortar, and plaster the out- 
side of the flues where they pass through the floors. 


Slides (slanting boards) must be put in each flue at the bottom, with an opening 
above to carry out the mortar droppings, and on completion of the chimneys the flues 
must be thoroughly cleaned out and the openings bricked up. 

All brick chimney breasts to be built plumb, straight and true, and all corners 
square. 

Build rough openings for fireplaces (with $x2-inch iron arch bars, turned up 2 
inches at the ends) and turn-trimmer arches to the same 2 feet wide on wooden cen- 
tres furnished and set by the carpenter. 

Build the ash pits under grates, as shown by plans, and provide and set a cast iron 
ash pit door and frame in each pit where shown or directed. 


Flue Lining.—Furnish and set in (the range and furnace flues) 8xr2-inch fire 
clay flue linings to start (2 feet) below the thimble and continued to the top of flue. 
The lining to be set in rich lime (cement) mortar, with joints scraped clean on the 
inside. 

Thimbles.—Provide and set in all flues, except grate flues, (sheet) iron thimbles, 
8 inches in diameter in furnace flue and 6 inches elsewhere, to be set 2 feet below 
the ceiling unless otherwise directed. Furnish bright tin stoppers for all thimbles 
except for (range and furnace.) 


Cold Air Duct.—Excavyate for and build the cold air duct and foundation for fur- 
nace as shown by drawings of hard-burned brick, laid in (Rosendale) cement mor- 
tar, and plastered smooth on the inside; also plaster the bottom of duct and furnace 
pit with cement mortar, on a 2-inch bed of sand. Cover the top of the air duct with 
(23) inch flagstone with joints neatly fitted and the edges cut true and square. The 
flagging to be furnished by (this) contractor 


SPECIFICATIONS. 381 


Fire Walls.—This contractor shall furnish and set, in Portland cement, salt- 
glazed tile copings on all fire walls not covered by stone or metal copings. The 
copings are to be 2 inches wider than the walls and to have lapped joints. 

Ventilators.—Leave ventilating openings in the foundation walls and between roof 
and ceiling joist, where shown on drawings, and put cast iron gratings in the open- 
ings. 

Cutting and Fitting.—This contractor shall do promptly and at the time the 
superintendent so directs, all cutting and fitting that may be required in connection 
with the mason work by other contractors to make their work come right, and shall 
make good after them. 

Setting [ronwork.—This contractor is to set all iron plates resting on the brick- 
work, and all steel beams supporting brick walls; also all iron lintels, tie-rods and 
skewbacks used in connection with brick arches or over openings. 

All such work will be furnished at the sidewalk by another contractor, and this 
contractor shall set the same in such position and at such height as the superintend- 
ent shall direct. All plates to be solidly bedded, true and level, in 1 to 2 fresh 
(Atlas) Portland cement mortar; the brickwork to be brought to such a height that 
the bedding joint shall not exceed 4 inch. 


[Where there is but little ironwork it is sometimes desirable to 
specify that the brick mason shall assist the carpenter in‘setting iron 
columns and. steel beams. Large contracts for iron and steel work 
are generally erected by a special contractor. All ironwork coming 
in connection with the stonework should be set by the same con- 
tractor that sets the stonework. | 


Setting Cut Stone.—The contractor for the stonework will set all belt courses, 
stone arches, coping, steps and other stone where fitting may be required, but this 
contractor shall set all single caps, sills and bond stones, the stone being delivered 
at the sidewalk. All such pieces of stone to be set in the best manner, in mortar as 
specified for the face brick. Sills to be bedded only at the ends. 

Setting Terra Cotta.—This contractor shall set all terra cotta work, indicated by 
pink color on the elevation drawings, in the best manner, in the same kind of mor- 
tar as is specified for the pressed brickwork. All terra cotta work that does not 
balance on the wall, or where indicated on the drawings, shall be securely tied to 
the backing by wrought iron anchors, of approved pattern, thoroughly bedded in 
cement mortar. (See also specifications for terra cotta work.) 

Cleaning Down and Pointing.—On completion of the brickwork this contractor 
is to thoroughly clean the face brick, using dilute muriatic acid and water, applied 
with ascrubbing brush. Care must be taken not to let the acid run over the cut stone. 
(Some stones are injured by acid and must be cleaned with water only.) While 
cleaning down this contractor is to point up under all sills, and wherever required to 
leave the wall in perfect condition. 


[Where there is little cut stonework the cleaning and pointing of 
it may also be included in this specification. | 


Outhouses—[ Customary only in Western cities. ]|—Build the outhouses and ash 
pit on the rear of the lot, as shown by plans, of hard-burned brick. Arch over the 
ash pit and give a heavy coat of (Portland) cement mortar. Leave an opening in 


382 BOULIIDING CONSTRCCTTION. 


the top for putting in ashes and provide an iron ring and cover for same. Furnish 
and set on the alley side at the grade a cast iron ash pit door and frame. 

Rubbish.—Clean out all boards, plank, mortar, brick and other rubbish caused 
by the brick masons, and remove from the building and grounds, on completion of 
the brickwork or when directed by the superintendent.* 

Brick Paving (for yards.)—Pave the yards and areas where so indicated on plans 
with good hard (vitrified) paving bricks, sound and square, laid flat, herring-bone 
fashion, on a bed of sand from (4) to (6) inches deep. 


{The necessary depth of sand varies with the quality of the soil, a 
stiff clay requiring the most sand; on such soils a bed of furnace 
cinders, etc., may be used to advantage before the sand is put down. | 


After the bricks are laid and graded (which should be about 1 inch in Io feet) to 
drain the water to the grade or to its proper outlet, the entire surface must be cov- 
ered with sand, which must be swept over the bricks until the joints are thoroughly 
filled. 


[For a better pavement the joints should be grouted in liquid 
cement mortar and the sand spread over afterward. Where extra 
thickness of wearing surface is required the bricks may be laid on 
edge and grouted or covered with sand as above. | 


Where brick gutters are shown the bricks are to be laid lengthways and the joints 
grouted in cement mortar. 
(For requirements for paving brick for streets and driveways, see Section 226.) 


SPECIFICATIONS FOR LAYING MASONRY IN FREEZING 
WEATHER.+ 


382.— Only in case of absolute necessity shall any masonry be laid in freezing 
weather. (See Sections 139 and 239.) 

Any masonry laid in freezing weather must not be pointed until warm weather in - 
the spring. Ifmecessary, masonry may be laid in freezing weather, provided the 
stone or brick are warmed sufficiently to remove ice from the suface and the mortar 
is mixed with brine made as follows: Dissolve 1 pound of salt in 18 gallons of water 
when the temperature is at 32° F., and add 1 ounce of salt for every degree the tem- 
perature is below 30° F., or enough salt, whatever the temperature, to prevent the 
mortar freezing. 


SPECIFICATIONS FOR FIREPROOFING.[ 


(HOLLOW TILE SYSTEM.) 


383.—The following specifications are intended to include the fireproofing of all 
the steel in the building, the filling in between the beams forming floors and roof, 
and the concreting over the same to the top of the floor strips. Also the covering of 





* If in the general conditions this paragraph may be omitted. 
+ Baker’s Treatise on Masonry Construction. 


+ Modeled after the specification for the Fort Dearborn Building, Chicago; Messrs. Jenney & 
Mundie, architects. 


SPECIFICATIONS. 333 


all columns, both those standing clear and those partly incased in the walls. Also 
the building of all tile partitions and tile vaults, and the walls of pent houses on the 
roof. 

This contractor shall furnish all material, including the mortar for setting 
‘the same, and shall do all his own hoisting and set all the work in a thorough, 
substantial and workmanlike manner, to the satisfaction of the superintendent. 

Mortar.—All work shall be laid in mortar composed of 3 parts of best fresh lime 
mortar and 1 part best (Louisville) cement, thoroughly mixed together just before 
using. Said lime mortar shall be composed of fresh-burned lime and clean, sharp 
sand in proportions best suited to this work. (For partitions Acme cement plaster 
may be used. See Section 344.) 

Floors.—All floors shal| be constructed of flat arches (of porous or semi-porous 
tile, end-method construction*) set in between the beams and of a shape that will 
give a uniform flat ceiling in the rooms below. The bottoms and projections of all 
beams and girders must be vrotected by projecting parts of tile or by separate beam 
slabs. In laying the floor arches every floor joint shall be filled full over its entire 
surface from top to bottom. No joints to exceed ;*; inch in thickness. 

No clipped or broken tiles will be allowed in the arches, and no cutting of arches 
will be permitted except where absolutely necessary and under the approval of the 
superintendent. All the arches must be formed to fit the various spans between floor 
beams, and in all cases special patterns of voussoirs or keys must be moulded and set 
where it is impossible to set the regular form. 

All floor arches, ten days after they are laid, and before they are concreted, shall 
be subject to a test of a roller, 15 inches face, and loaded so as to weigh 1,500 
pounds, rolled over them in any direction. 


[This test is only intended to provide against poor workmanship 
and improper setting of the tile. If any system whose strength has 
not been fully demonstrated is to be used, it should be subjected to 
a more severe test. See Section 299. | 


Columns.—Al\ columns shall be covered with (porous) column tile held by metal 
clamps, both in horizontal and vertical joints. These column protections shall be so 
made as to conform with the city ordinance. 


[Where the city ordinance is not sufficiently strict on this point, 
the specifications should be more definite as to the shape of the tile. 
See Section 318. | 


Roof.—The roof shall be eonstructed in the same way as the floors, except that the 
top of the tile shall be flush with the beams and the soffits may be segmental, with 
raised skewbacks. 

Partitions.—Build all partitions shown on the several plans of (porous, semi- 
porous or dense) hollow tile, 4 inches thick in the first and second stories and 3 
inches thick in all other stories except the hall partitions, which are to be 4 
inches thick throughout the building. 

In glazed partitions the lower parts and all parts other than the sash and frames 
shall be of tile. 


* This clause is not in the Fort Dearborn specification. 


384 BOLLE DING CONST RGGLTLION: 


The tiles shall be set breaking joints and to be tied with metal ties or clamps. 

Furring for False Beams and Cornices.—This contractor is also to furnish and 
put in place tile furring for the cornice and false beams in the (bank and assembly 
hall), to be of profiles and sections as shown by drawings. (See Section 349.) 

The cove and ceiling pieces of the cornice, and all parts of the beams, to have 
holes east for bolts, spaced not over 12 inches apart and at least two bolts for each 
piece. The furring to be properly and securely mitred at angles and all to be prop- 
erly bedded, with close joints, in mortar as specified above. 


All suspended pieces to be substantially fastened in place by }-inch diameter 
T-head bolts, spaced not over 12 inches apart, with nuts and washers to each. 

(Or, all furring for cornices and false beams will be put up bythe contractor for 
plastering. ) 

Wall Furring.—Fur the outside walls in finished portions of basement with 
3-inch (porous, semi-porous or dense) tile so as to form a vertical and true surface for 
tiling. The tiles to be set with the hollow spaces vertical, and to be securely fas- 
tened to the wall by flat-headed spikes. 

Miscellaneous.—All tile work shall be straight and true.. 

All tiles of every kind must be thoroughly burned and free from serious cracks or 
checks, or other damages, and shall be laid in a proper and workmanlike manner. 

No centres to be lowered until the mortar has set hard. 

All structural steel on which the strength of the building depends in any way, 
including wind bracing, shall be protected by fireproof covering of approved shape 
and substantially fixed in place. 

All tilework to be left in suitable condition for plastering. 

Concreting.—This contractor shall fill in on top of the floor arches with con- 
crete composed of I part (natural) cement mortar and 4 parts of screened boiler 
cinders, to be leveled off at the top of the highest beams or girders, and after the 
floor strips are set by the carpenter to be filled in between said strips with the same 
concrete pressed down hard with a reasonably true surface } inch below the top of 
the strips. 

All damage to tile work to be repaired before the concrete is laid. 

Roof.—This contractor shall cover the surface of the roof tiles with I to 3 (nat- 
ural) cement mortar of sufficient thickness to come $ inch above the top flanges of 
beams and girders, and to give the desired pitch to the roof, with a reasonably uniform 
surface. 


[If the tops of the tiles are more than } inch below the tops of the 
girders, concrete may be used for filling to top of girders and ? inch 
of mortar applied above. | 


Outside Walls.—The outside walls of pent house on roof to be built of (4-inch) 
hard-burnt wall tile, clamped together, and set in mortar as above specified. Every 
joint, both vertical and horizontal, to be thoroughly filled over its entire surface with 
mortar, and all outside joints to be struck in a neat and workmanlike manner. 


This contractor shall give a written guarantee that the outside face of these tile 
will stand the weather for (five) years dating from the completion of the wall, and 
agree to replace any tile injured by the weather, either in winter or summer during 
said period, promptly and at his own expense. 


SPECIFICATIONS. 385 


SPECIFICATIONS FOR TERRA COTTA TRIMMINGS.* 


384.—Material.—This contractor shall furnish and set wherever called for on 
drawings terra cotta to exactly match in color the sample submitted, all in strict 
accordance with detail drawings. Material for all terra cotta to be carefully selected 
clay, left in perfect condition after burning, and uniform in color. All pieces to be 
perfectly straight and true, and with mould of uniform size where continuous. No 
-warped or discolored pieces will be allowed. This contractor to furnish a sufficient 
number of over pieces, so as to avoid all delay. 


Modeling.—All work shall be carefully modeled by skilled workmen, in strict 
accordance with detail drawings, and models shall be submitted for architect’s 
approval before the work is burned. No work burnt without such approval will be 
accepted by the architects unless perfectly satisfactory. 


Mortar.—All mortar used for exposed joints in terracotta work shall be composed 
of lime putty, colored with (Pecora) or (Peerless) mortar stains to match the mortar 
used for pressed brickwork. 

Ornamental. Fronts, Belt Courses, Bands.—This contractor shall furnish and set 
all ornamental terra cotta, belt courses and bands, as shown on elevations or sections 
or where otherwise indicated, in strict accordance with detail drawings. All terra 
cotta work to be secured to the ironwork in the most approved manner, with sub- 
stantial wronght iron or copper anchors, and thoroughly bedded in cement mortar. 
All horizontal joints to have lap joints. All projecting courses to have drips formed 
on under side. 

Caps and Jambs, Sills.—All caps and jambs where indicated as terra cotta will 
be constructed in strict accordance with detail drawings. All sills and belt courses 
to have countersunk cement joints as directed by thesuperintendent. All projecting 
sills to have drips formed on under side and all sills shall be raggled for hoop iron, 
which shall be bedded by this contractor in cement mortar. 

Terra Cotta Mullions.—A\\ ornamental mullions of terra cotta to be secured to 
metal uprights in approved manner, and well bedded and slushed with cement 
moitar. 

Cornice.—This contractor shall construct the cornice in strict accordance with detail 
drawings, with sufficient projection through walls and approved anchorage to the 
metal work to make them thoroughly secure. This contractor to furnish all neces- 
sary anchors. Form raggle in cornice as shown for connection of gutter, this raggle 
to be on face of terra cotta. Leave openings in cornice for down-spouts as shown. 

Anchors.—This contractor shall furnish all anchors of substantial wrought iron or 
copper, for the proper support and anchoring of all terra cotta used in his work. All 
terra cotta to be drawn to tight and accurate joints to entire satisfaction of the super- 
intendent. All terra cotta must fit the supporting metal work exactly. 

Cutting and Filting.—This contractor shall do all fitting necessary to make his 
work perfect in every particular, all possible cutting and fitting to be done at the 
factory before delivery. 

Protection of Terra Cotta,—All projecting terra cotta shall be protected with 
sound plank during erection of the building by terra cotta contractor, said protection 
pieces to be removed on cleaning down the bui'ding. 





* From specifications of Fort Dearborn Building. — 


386 ‘DB OLEDING CON SLE OCLLION. 


Cleaning Down.—This ccntractor shall carefully clean down all terra cotta work 
on completion of building, when directed by the superintendent, and shall carefully 
point up all joints before leaving the work. 


SPECIFICATIONS FOR LATHING AND PLASTERING. 


(ORDINARY WORK.) 


385.—Lathing.—Lath all (walls) partitions, ceilings, and all furring, studding, 
under side of stairs, etc., with best quality of pine (spruce) lath, free from sap, bark 
or dead knots, and of full thickness. To be laid 2 inch apart on the ceilings and 4 
inch or more on the walls, with four (five) nailings to the lath and joints broken every 
18 inches; all to be put on horizontally. Under no circumstances must laths stop 
and form a long, straight vertical joint, nor any lath be put on vertically to finish out 
to angles or corners; neither shall any lath run through angles and behind studding 
from one room to another. All corners must be made solid before lathing. Should 
the lathers find any angles not made solid, or any furring or studding not properly 
secured, they are to stop and notify the carpenter to n.ake permanent the same. 

Metal Lathing.—Lath walls or partitions in front of hot-air pipes with metal 
lathing approved by the architect. Cover all recesses in brick walls that are to be 
plastered, all wood lintels and wherever woodwork joins the brick walls (if latter are 
not furred) with (Bostwick) or expanded metal lathing properly put up and secured. 

Plastering—Sack-Plastering (for frame buildings).—Back-plaster the whole of 
the exterior walls from sill to plate between the studs, also between the rafters of 
finished portion of attic, on laths nailed horizontally, 3 inch apart, to other laths or 
vertical strips put on the inside of the boarding, with one heavy coat of lime and hair 
mortar, well troweled and made tight against the studs, girts, plates and rafters. 

One-Coat Work.—Plaster the (basement ceiling) one heavy coat of rich lime and 
hair mortar, well troweled and smoothed. 

Three-Coat Work.—All other walls, partitions, ceilings and soffits throughout the 
building to be plastered three coats in the best manner. 

The first or scratch coat to be made of first qua@ity (Rockland) lump lime, clean, 
sharp bank (river) sand, free from loam and salt, and best quality clean, long cattle 
hair, mixed in the proportion of 54 barrels of sand and 1} bushels of hair to each 
cask or each 200 pounds of lump lime To be thoroughly mixed by continued work- 
ing and stacked in the rough for at least (7) days before putting on. The hair and 
sand are not to be mixed with the lime until the lime has been slaked at least six 
hours. 

The scratch coat to be properly put on and applied with sufficient force to give a 
good clinch, and to be well scratched and allowed to dry before the brown coat is 
put on. 

The second or brown coat to be mixed same as the scratch coat (except that 6} 
barrels of sand and but } bushel of hair to 1 of lime may be used). Level and float 
up the brown coat and make it true at all points. 

White Coat.—The third coat (except in the halls and ee room) to be mixed 
with lime putty, plaster of Paris and marble dust (or lime putty and King’s Superfine 
Windsor Cement), thoroughly troweled and brushed to a hard, smooth surface. 

Sand Finish.—TYhe third coat in halls and dining room to be composed of lime 
putty and clean-washed (beach) sand, floated with a wooden or cork-faced float to an 
even surface, equal to No. I sandpaper. 


wi OLPICATLON §. 387 


All lathing and plastering to extend clear down to the floor ; all walls to be straight 
and plumb and even with grounds ; all angles to be maintained sharp and regular in 
form. : 

Plaster Cornices, etc.—Run all around the (parlor) a plaster*stucco cornice, to 
extend (8) inches on the ceiling and (6) inches on the wall, and to be run in strict 
accordance with detail drawing. Run all beads, quirks, etc., to angles of beam 
soffits as indicated on drawings, and finish at each end of beams with cast plaster 
brackets, modeled according to the architect’s full-size detail. 

Put up cast plaster centrepieces in (3) rooms, for which allow the sum of ($25). the 
same to be expended under the direction of the architect. 

The-plasterer must clear out all boards, planks, horses, mortar, dirt and all loose 
rubbish made by him or his men, and remove from the rooms and premises, as fast 
as the several stories are plastered, and leave the floors broom clean. Patch up and 
repair the plastering after the carpenters and other mechanics in a skillful manner 
and leave the work perfect on completion. 

Two-Coat Work.—The following is the usual form of specification for house 
work in New England : 

All walls, ceilings, soffits and partitions throughout the (first and second stories 
and attic) to be plastered two coats in the very best manner. 

‘«The first coat to be of best quality (Rockland) lime and clean, sharp sand, well 
mixed with 1} bushels of best long cattle hair to each cask of lime; to be thoroughly 
worked and stacked at least one week before using in some sheltered place, but not 
in the cellar of the house; all to be well troweled, straightened with a straight-edge 
and made perfectly true and brought well up to the grounds. 

‘“The second or ‘skim’ coat to be of best (Rockland) lime putty and washed 
(beach) sand, troweled to a hard, smooth surface.” 


SPECIFICATIONS FOR HARD PLASTERING. 


386.— All walls, ceilings, soffits and partitions throughout the building to be 
plastered three coats, in the best manner, as specified below. 

The first and second coats to be of (Acme) cement plaster or dry mortar—the 
first coat on lath work to be fibred material. 

The material to be mixed with clean water to the proper consistency and applied 
in the usual way. The first coat to be scratched or broomed to forma rough surface 
for brown coat. Apply the brown coat as soon as the scratch coat is two-thirds dry 
or has set sufficiently to receive it, bringing the mortar out even with the grounds 
and to atrue surface. Scratch roughly for all stucco cornices and mouldings. 

Sand Finish.—After the brown coat has been on twenty-four hours finish the 
walls and ceiling of (hall and vestibules) with (Windsor) sand finish, mixed with clean 
water only and floated to a true surface with clear soft pine or cork-faced floats. 


[Or lime putty and sand may be used as in ordinary plastering. | 

Hard Finish.—When the browning is two-thirds dry, finish all other walls and 
ceilings throughout the building with a white coat made of equal parts of lime putty 
and plaster of Paris, troweled and brushed to a hard and uniform surface. 

[For a better grade of finish add a quart of marble dust to each 
batch of plaster, or use Windsor cement instead of plaster of Paris.] 

All brick and tile walls and all wood laths to be well wet just before plastering. 


388 BULLDING CONSTRUCTION. 


Only as much mortar as can be used within one hour is to be mixed at one time, 
and under no circumstances shall any mortar that has commenced to set be retem- 
pered. . 

The plasterer must strictly observe and follow the directions accompanying the 
plaster. 


[Specify for patching, cornices, etc., as in Section 385. | 


SPECIFICATIONS FOR WIRE LATHING WITH METAL 
FURRING. 


(OVER WOODWORK.) 


This contractor is to fur all ceilings, soffits of stairs, all timber beams and 
posts, and both sides of all wood partitions throughout the building with Ham- 
mond’s metal furring with (1)-inch bearings, the stiffening rods to be placed (6) 
(see Section 333) inches on centres, across floor beams and studding, and a line of 
furring to be placed on each side of each angle, as near the angle as possible. 
Posts and girders to be furred lengthways, with a line on each angle, and every 74 
inches between. 


[If the architect does not wish to specify this furring he can specify 
35x4-inch corrugated band iron, put up with 14-inch staples. | 


All furring to be substantially secured with 2-inch No. 13 steel staples (see 
Section 333) and to be set to give a true and even surface for the lathing. 

Cover all the above surfaces with (plain, painted, japanned, galvanized) wire 
lathing (24) (2{x5) mesh, No. (20) wire, tightly stretched and secured with (2)-inch 
No. 13 steel staples (see Section 333) driven over the lath and furring at each bear- 
ing where the lathing runs crossways of the timbers, and every (6) inches where the 
bearings run parallel with the timbers. The lathing to be lapped at least 4 inch 
where the strips come together and 14 or 2 inches at all angles of walls or wall and 
ceiling. 

SPECIFICATIONS FOR STIFFENED WIRE LATHING. 


(OVER WOOD AND BRICKWORK.) 


Cover all ceilings, soffits of stairs, both sides of all wood partitions, and all 
wooden posts and girders throughout the building with the (Roebling) stiffened 
wire lath, painted, No. 20 gauge, and (2}x5) (2}x2}) mesh, with 3-inch V-ribs. 
(For the posts and girders and on planking #-inch ribs will give better protection 
both from fire and dry rot.) 

The lathing to be applied with the ribs running at right angles to the beams; to 
be tightly stretched and secured with galvanized steel nails, driven through each 
end of each rib, and at every bearing between and every g inches on timbers and 
planking. The strips to lap on a joist in every case and to be carried down 2 
inches on the walls. Care must be exercised to see that no holes are left at any 
place in the ceiling where the plastering can drop off and fire enter. 

Lath the outside walls of finished portion of basement, from floor to ceiling, with 
(Roebling) stiffened lathing, painted, No. 20 gauge, (2$x5) mesh and 14-inch V-ribs. 
To be tightly stretched, lapped 1 inch and secured to the walls with 10d. steel 
nails driven through the ribs every 84 inches and at each end. The lathing to be 
applied with the stiffening bars vertical. All the above lathing to be done in the 
most approved manner so as to give a firm surface upon which to apply the plaster. 


SPECIFICATIONS. 389 


SPECIFICATIONS FOR METAL LATH ON IRONWORK. 


This contractor is tofurnish and put up in a substantial manner all iron furring 
and lathing for enclosing the posts and girders and for forming the cornices, as 
shown on the drawings and as specified below. The lathing to be well lapped on 
to wal!s and ceilings to make a tight job. 


Girders.—All girders projecting below the level of ceilings shall be encased by 
wire lathing, stiffened with a j-inch solid rib. The lathing to be rigidly supported 
by light iron furring built out to correct outline as shown onthe plans. The fur- 
ring to be so designed that the weight of the plaster and falsework will be supportea 
by the girder and so as to afford a firm surface for plastering. 


Cornices.—Full-size details of all cornice work will be supplied by the architects 
at the proper time. Iron brackets, bent to correct outline and spaced not more 
than 18 inches apart, shall be secured in position in the best manner and well 
braced. Over this falsework wire lathing, stiffened with a }-inch steel rib, shall be 
laced so as to conform with the profile of the brackets and produce a smooth, firm 
surface for plastering. 

Columns.—All columns not enclosed in brickwork are to be wire lathed. Suit- 
able light iron furring shall be provided so as to offset the lathing at least 2 inches. 
from the ironwork and finish round or square as shown on the plans. The lath- 
ing to be stiffened with a 4-inch solid rib woven in every 7} inches. 


All other exposed tronwork shall be suitably encased with wire lathing supported 
whenever necessary by light iron furring, and in all cases providing an air space of 
at least 1 inch between the ironwork and the plaster. 

All the above lathing to be painted (galvanized), of No, 20 gauge and (2}xs5) 
mesh, and to be securely laced to the furring with No. 19 galvanized lacing wire. 

(All work here contemplated must comply with the requirements of the Depart- 


ment of Building.) 
SOLID PARTITIONS. 


(METAL LATH AND STUDDING.) 


This contractor is to provide all metal work, and erect the partitions indicated by 
(gray) color or otherwise marked on the plans, and leave them in perfect condition 
for the plasterer. Wood furring will be furnished in pieces of the proper size by 
the carpenter, but this contractor is to secure them to the metal work. The above 
partitions to be formed of studs of $x$-inch channel iron, placed 16 inches centre 
to centre for partitions (11) feet high or less and 12 inches centre to centre for par- 
titions more than (11) feet in height. All openings to be framed with 1x1-inch by 
#s-inch angle irons, 


Studs must be securely fastened at top and bottom, and grounds for door and 
window openings must be firmly secured to the studs.. Grounds for nailing of base, 
chair rail, picture moulds, etc., must be fitted and fastened in true and straight, $ 
inch over the line of studs on face side of partition and } inch over line of studs on 
reverse side, 1} inches total thickness. 


2. After grounds are put on the face side of partition to be covered with (Bost- 
wick steel lath put on with the loops inward or between the studs); the sheets of 
lath must come close together or lap on horizontal joints and the vertical joints must ~ 
be broken properly ; the lath must be secured by nailing on with trunk nails, driven 


390 BUILDING CONSTRUCTION. 


through alongside of stud and clinched around behind it, each nail being on opposite 
side of stud from the one above and below it. The metal work must be properly 
braced to hold it in position until the mortar has become firm. 

(The bracing should be a straight-edged flooring board put on over the lath, and 
staples set around the studs driven into the board can be easily drawn afterward, 
leaving only I inch of strip to fill in on face of partition and the staple holes on 
reverse after partitions become rigid.) 


[For wire lathing specify as follows instead of as in paragraph 2. | 


3. After grounds are put on cover one side of the partition with No. 20 painted 
(24x5) mesh wire lathing, stiffened with a }-inch solid steel rib woven in at intervals 
of 74 inches, the rods to run crossways of the studs. The lathing to be firmly 
secured to the studding by No. 19 galvanized lacing wire. 


SPECIFICATIONS FOR THE “ROEBLING FIREPROOF 
FLOOR.” 

[This specification is given as a guide in preparing specifications 
for this and similar floors. Most of the various fireproofing compa- 
nies have printed specifications for their systems, which they furnish 
to architects on application. | 


The floor construction to be used in this building shall be that known as the 
‘*Roebling System,” consisting of a steel-ribbed wire cloth and concrete arch with 
ceilings suspended below the level of the floor beams. A continuous air space 
between the floor and ceiling and around the girders shall be provided. 

The wire centring for the floors shall consist of No. 19, four-warp two-filling 
wire cloth stiffened with ? to }-inch steel rods woven into the cloth at intervals of 
about 9 inches. This centring shall be sprung in between the I-beams in the 
form of an arch with the ends of the rods abutting against the beams. The sheets 
to be well lapped and securely laced. Over the crown of this centring one or 
more ;°;-inch steel rods shall be laced parallel to the beams to secure proper longi 
tudinal bracing. 

In all spans over 3 feet 6 inches a heavy galvanized wire shall be dropped down 
from the stiffening rib of the arch at intervals of not over 3 feet to support the 
ceiling. 

Over the wire arch so constructed cinder concrete mixed in the proportions of 1 
part of high-grade Portland cement to 2 parts of sharp sand and 5 parts of clean 
cinder shall be laid to a sufficient thickness to secure the required strength, as des- 
ignated elsewhere in these specifications. The concrete generally to be leveled 
(2 inches above) the top of the floor beams where wood floors are specified, and to 
the specified levels where other than wood floors are designated. 

Every alternate nailing-sleeper to be imbedded in concrete so as to form a fire 
stop. These sleepers to be supplied and placed in position over the beams under 
‘the carpenter’s contract. 

The floors to be subject to test at any point that may be designated by the archi- 
tect, and at any time after the concrete is fifteen days old. The floor shall in all 
cases develop a strength of 1,000 pounds per square foot when the load is concen- 
trated, and similarly a strength of 600 pounds per square foot when the load is 
uniformly distributed over one-half of the span. 


APPENDIX. 


The following tables relating to the properties and chemical composition 
of building stones, and to stone buildings, have been compiled by the 
author from various sources (principally from several volumes of Stove and 
Merrill’s Stones for Lutlding and Decoration), and are believed to be 


reliable : 


TABLE A, 


SHOWING THE WEIGHT, CRUSHING STRENGTH AND RATIO OF ABSORPTION 
OF VARIOUS BUILDING STONES. 





Kind of Stone. 


e@eoeveees 


Granite (Hornblende)... 


Granite (Hornblende). . 


“é 





Locality. 


Vinalhaven, Me........ 


Dixtisland Me. 7.25. 


.|Hurricane Island, Me... 
ce 66 


Fox Island, Me...... ae 
Keeneain tit. coe eee 
Cape Ann, Mass........ 


ore eevee eee 


; WLI OTG ees ONT to. tas oes 


NVCSTCLUV A kta ka tiny ein es 


Huron Island, Mich.... 


.|East Saint Cloud, Minn. 


.|Saint Cloud, Minn..... 


Granite (Gabbro)....... Duluths Minn. ois 3s 
Granite (Biotite).......: BE ATEVIOWN 2 oN cay sce < 
PAS OY yin cepi es iat Staten Island, N. Y.... 
ERD” be Be aie iheatc-ete Crinnisone GOlos., <u. 


Limestone (Dolomite)... 


ac 


Limestone (Oolitic)..... 
ae 


Limestone (Dolomite)... 


oe 


foliate Lb weees testes 


Re LCeINOD i Libres = cakes 
fe SENT Tey ie U1 ie reer 


Bedlerd 2100 «nse ce 2 


Eos (Dutt) 


MISSION a LNG. ee eee aes 


Stillwater, Minn........ 


é 





ee 


* Burst suddenly. 


+ Cracked before bursting 


Approximate 
size of cube 


2 


2 


in inches. 














Position. 





Bed 


Edge 
Bed 
Bed 
Bed 
Bed 
\ Edge 


Edge 
Bed 
Edge 
Bed 
1 Edge 
Bed 
Edge 
Bed 
Bed 
Bed 
Bed 
1 Edge 
Bed 
Edge 
Bed 
Bed 
Bed 


1 Bed 
Edge 
Bed 

Edge 





Strength per 
square inch. 


15,698 


15,000* 
14,425* 
14,937* 
14,875* 
10,375 
12,423* 
19, 500* 
16, 300 i 
19,750 § 
17,750} 
14,750+ 
22,610 
17,500 
14,937* 
18,125 
14,425 
25,000 
26,250 
16,000 
18.500 
17,631 
18, 250+ 
22,250t 
12,976 
15,594 
14,585 
14,634 
14,775" 
12,000* 
9,687* 
6,500 
10,125 
14,000} 
8,625 
25,000 | 
25,000 } 
10,750 
12,750 

















Sars : 
2.8 |38 
a) ty oo 
Se [S 8 
Vv Wn 
Be Mx 

1163 oats 
EOS ae ares 
TOGO ule see 
TOGLOM ee er 
TOA 4. a ohe 
166 lado 
16332 iis 
166.2 . 
168.7 oe 
T6bsG eee 
1602 07]56) 
164.4 | aby 
163.7 | s¢3 
168.2 ° 
168.2 aay 
175 
162.2 ° 
178.8 . 
006 ° 
s006"T2 << 
160 oy 
165.3 | ay 
160.6 tis 
147. 1) ve 
152.4 | gy 
144.3 | os 
E720 SET 
160.4 | zy 








+ Tests made at U. S. Arsenal, Watertown, Mass, 


oo 


TABLE A.—(Continued.) 


Kind of Stone. 


Limestone (Dolomite)... 


Limestone (Magnesian).. 


66 


e@eoeoee 


Marble (Pink) 52.0 ...4: 
Marble (White) 


Marble (Dark Pink)..... 
Sandstone (Brownstone). 


6c 
ee 


.|‘‘ Etowah,” Georgia. ... 
66 


‘Kennesaw, 


Locality. 


Red Wing, Minn....... 
Glens:FallssNiv...e. 


..|Lake Champlain, N. Y. 


Lee-Mass. cease 


.|Cantre Rutland, Vt.. ; ‘ 


DOrsSttacy tie ston ra bre tee 
“Cherokee,” Georgia... 


46 


“Creole, ? Georgias....: 
«6 


ae 


6 
” 


Georgia. . 
C6 


East Tennessee......... 
cé 


“¢ 


ae 


Portland, Conn.. i ! 


ad .'(Cromwell, Conn7.. .. . « 
Sandstone (Con.) 

as Brown (soft)..|East Longmeadow, Mass 
66 “6 (hard). “6 66 
ae (Kibbe} a... as Ss 
J eee ee ort PotsGains) Noss acts iene 
he (hlac.color)..:|Medina; = NaY.... . «cum 
- (ight)s sess North Amherst, Ohio... 
a OS ety elas Gist Berea. OMi0rete. ot eco. 
ee ha ate VRE | Cleveland, Ohio........ 
ss AIG Tate s ye Hummelstown, Pa...... 
ss te De dest Raters Pong dus Lace Wis; ssa. 
oe (hard, red)...|Saint Vrains, Colo...... 
uf (hard, gray)..|Fort Collins, Colo...... 
sf fs MOU ACOlO. cee ccc venace a 


(light red)... i 


* Burst suddenly. 


Nianitou.- (Old. ie eer 
oe 


ereeeoe ese 


size of cube 
in inches. 


Approximate 


Position. 


BUILDING CONSTRUCTION. 


Strength per 
square inch. 





SS SS SS | ee 


iS) 


Nd 


SER HEHEHE HE HEH 


bo 


thane) 


HNHYWWNNHDANNHAPHAHAHWAHHAPHANAD NHN 


Wht ro 


tHe HEH HE 


Bed 


Bed 
Edge 
Bed 
Bed 
Bed 
Bed 
Bed 
Bed 
Bed 
Bed 
Bed 
Bed 
Bed 








23,000 
23,250 
11,475" 
10,759 
25,000° 
21,500 
22,900 
10, 746 
8,670 
10,976 
13,415 
11,522 
12,078 
I1I,420 
15,512 
10,642 
14,217 
13,888 
8,354 
10,771 
15,750 
7,212 
14,812 
13,750 
13,980 
13,330 
13,920 
15,020 
9,900 
12,250 


8,437 
14,085 
12,619 
18,401 
42,000 
17,250 

5,450 

6,212 

6,510 

8,222 

6, 800 
12,810 

6,237 
II,505 
II, 707 
10,514 
II,000 

6,000 





+ Cracked before bursting. 


t Tests made at U S. Arsenal, Watertown, Mass. 











is S 
a8 36.2 
re he ° a 
® ZY 
Se a 

162.2 ty 

168.8 ese 

DUE Meas e 

106, Belaene 

167.8 ° 

BA 1250 

eoeereee 1240 

eoeceee 1480 

S40 6 ors T0770 

"Average 
of 6 t ests 

150.6 | ge 

133-7 | 19 

135.8 | yy 

134 BT 

140 a7 

138.8 | 

149.3*|.O61 

140.7 |.072 

141.2 |.066 

140 a 


APPENDIX. | 393 


TABLE A.—(Continued.) 


SLATE, 





Modulus of | Weight per 





Locality. Rupture. etiatiock: Porosity. |Corrodibility. 
PURI T CNDioe viele cae seh os 7,150 lbs. 173.2 0.238 0.547 
Gidtbangor, Venn 2.5 5's et ose 2-01 9,810 ‘ 17328 0.145 0.446 
Peach bottom region, Penn.....} 11,260 ‘ 180.4 0.224 0.226 
TABLE B. 


SHOWING THE CHEMICAL COMPOSITION OF VARIOUS BUILDING STONES.* 



































GRANITES. 
ss} 3 
5 A @ ln Ss 
Description. Locality. = E oe E g A 
N oom ay so) 
a Oo eo a z 
Tight... ste. «ears Monsony Massie. seas 73247 15.07 Te TSy( Aedo1 S207 
Darker css eccke S Sot ete tet POOLSS 18.83 2, O01 5. O4 403,75 
Hornblende........ East Saint Cloud, Minn.| 65.12 16.96 4.69 | 4.77 | 5.25 
re Ag A gre eee ey Paw ee! 12.68 BEG2 HT 28e183. 00 
Dia bOsefvee cece Duluth eMinnites <5. 50.43 23.55 17.03 } An 79 | 2940 
NSA DDTOSs 2 oo earns 4 Renita aes vale}  4Ou5E 13.79 10734 71.9.34: 1.60 
SANDSTONES. 
wn 
ee 5 = ee a Oe 
Description. Locality. = OS & ae 
a = oe A eee 
< a 
Maynard (red)......|E. Longmeadow, Mass..| 79.38 OBS apn edge 402.57 22.79 
Worcester (red)..<.°. 7 aS a tnbare) 5.95 7G 27 et Os 
Kibbe! quartz. .. 3. wh EI Pay RSS te ol 9.44 3.54 JO" 4aAO 
Brownstone<:.-....|Portland, Conn.........| 69.904 13.15 2.48 300.) 15ar 
= Meat cuaeints he Paes 70.11 13.49 | 4.85 2230. 72474 
Sandstone........../Stony Point, Mich...... 84.57 5.90 | 6.48 ee LOS 
Portage Entry (red).|Lake Superior, Mich....| 94.73 O230iis 1204s 150000 .83 
Ouariziteg. as. cai.c% Pipestone; Minn. a... 84.52 52°33 lly A aC ee a See ae eH 
Bulan one aan Amherst, (OMIOpe ss a s.ee'e 4 2 OF 200ul) esis ys 1.00 I.15 2 
Berea...... ROE Bereay Olona: 1. ate as QOS My bss 1.68 255 Ee 
Euclid Bluestone...|Euclid County, Ohio....| 95.00 2.50 T00 (weet eG 
Columbia sis .%,< seat Columbia, Ohio........ DORE Oe ws cisy s Ae oes) [e200 
REG ards e cies alae PaAurele Run, (Pa rey, cles GAtOO UN ase es 1.90 PerOuersOe 
Pee aes ore toe Grattona Ohio. co... 14 87.66 ree S752 rab ieee’ 
Sandstone... .<.....\Fond du Lac, Minn....|" 78.24 10.88 3.83 SOS) Tha ace 
ty yer mons «lh iagstafi, Arizona. ...... 79.19 3.75 Testa 20 
1030 |e 3508 


pe VEPs Dorchester, N. Brunsw’k| 82.52 TeOzele 3.55 








* Some minor elements occurring in very small quantities and not affecting the durability of the stone 
are omitted. 
+ Potash and soda. 


394 : BUILDING CONSTRUCTION. 


TABLE B.—(Continued.) 


LIMESTONES OTHER THAN MARBLES. 





























v So Saisie eo ae 
Be SBE Pele clo zsss| Fy 
Description. Locality. 2 = Se é = e fe ga 58 
oo) Sl Sia eo 
Sie sie. Meee Sg al aS 
MIOIOWULE: Gig ctstey nna sats 3) OMNI L cs sates ated BY CA ae eh 2.30'7.00, 15.90 6.90 
ce ara | 
ON ies antecs cate en eeerace Bedford, Indjvas..s are 96.60] 0.13] 0.98 0.500.96 
ed en ee Pr, iS nea asics «ach 9] P20 6s 3710-40 42 tee ty O02 tO 
eran (OUI) oe or eet ae fe : eS T2014 Ona8910> 390i iis apes O US ie.S. o. 
BREEN Lo ern’ b ectetens as 159726) OF3710840).), enh a ets OOuar 
BAe ec «aro vies etaeteteho ake Spencer, Ind.. wits | QO. 00he Oc BIO. OL 0.70,0.92 
Ooline sis cs aecee oe Bowling Green, Ky.. 1 OS281) el. 1210.40), I.42|1.76 
DDOlOMIMEs <..% ats one ok Minneapolis, Minn..... 54.53| 36 |0.903. “16 16, 22/0.375 
NOG. ccs 5 o/stetta te ee evel Cy eee 41.88] 24.55)4.03).. 20.03) 025.4 
SIP Lear dake deere ot ns ee 75.48] 6.81 1.70|.... 14.45|1.60 
pS me Kasota, Minn... dea cos 21 04025 01037. 53/1, O0lo. cin 400 nae 
th Rate coateute. uieerenet Stillwater, Minn: :.....). 50.225 5397239/0,. 78,0. 0415 -O- 54pcns ws 
ee) ENTE Qoso moh Frontenac, Minn....... BAY78\, 42.5310. 3010.92). 2 OSnanaes 
Dimestonein .2% eee ce Dayton, Ohio. 5 ..-. 92.40) <leIO|OeSohkaw full JOl. ao 
Dolomites sees. Springfield, Ohio....... 54701044. 0910. 2010.1 teen LO) see ees 
Limestone (Caen).......|Aubigney, France...... QT POO ata Arse ap aia EVO: 
- (Oolitic).....|Portland, England...... 95-16] 1.20|0.50}....| 1.20/1.94 
MARBLES, 
fae om Sug x 
if | so | ee4| 992) 22 
Description. Locality. es Sauls S's an 
uw = n 
53 [| 8s" | 642) fm 
Dolomitei.. se << sees. | PLeStin os, N wt) oy a ace 52.82 45.78 : : 
A WILE) os cnencene Sing: Sings Nee Veen 53.24 | 45.89 ‘ : 
ae reg MEL Sy res A ‘Tuckahoe Nios... « 61.75 38.25 ererehe ‘ 
eS ENC WDILG): corer sees Pleasantville, N-'Y:...1) 54.62 | 45.04 | "0.23 “ 
-. SE Stata elec ates Ger Maser ae octet a orecs 54.62 | 43.93 . 365 «$e 
Limestone (white)........ Rutland, AG age werhi Ap arse Qye7 371 meee. .59 1.68 
S (greenish)...... S5 245 i aie caters 14.55 iy ais 
ss (white)}i\. 2 ch so West Rutland, ‘Vt... 98.00 fae Odie 0.57 
se (bluish gray)... Proctor, pvt aes : 98.37 | 0.79 0.005 0.63 
Mt (light Coloredjerewer ie as s.0 sawn 96.30 3.06 eseaet 0.63 
Se Eas ea eee East Tennéssee.....° 98.78 0.67 | 0.26 .08 
Georgia Marble Co....... ISCOT UIA wok sce s suse te 07.42 1.60 .26 wishes 
Southern Marble Co..... AN RADA aera erp 98.96 0.13 22 
te Seer ccetaas OME dere cia Cee 98.52 0.88 Pe 
Carrara (white)..... Sree BLA LV etic vase. sb ciel otet 99.24 0.28 oe Ee 
g ahhta nsw alte a mS ele ye pals cavie ew clena te tmeOoe su 0.9 1.08 0.16 


APPENDIX. 395 


TABLE B.—(Continued.) 


ONYX MARBLES, 























© = vo 3S o o 
a. = St aq 
~ A, Ss 

Source. Color. rah Ge 5 8 = 5 8 = 
Hacienda del Carmen, Mexico..... Light préen... 3). .....-|171.87| 89.36] -3. 00 |-52¢ 
Mayers Station, Arizona: .:<.... 2. TEs Se oo sa LT 287) 902-03) .0.56: 14550 
44 dP nasty tas sicixttts VGC. DOW War wires os oe 166.87] 93.82] 0.53 | 4.06 
Pes reck AtizONa ves. 6 shee ven Pipe green. dee ees 1k FL. 07) 03-46) 1-07/).5 19 
SISSIES LY OA TOP IIS we alate a slats Dark amber. fox’. « «<5s E701 02) O5sday 25205) 6 ss 

pulp War Greeks, 1) eles wis ents ici! Wo nce om wet 0 y pclstal Men aan ae el oe 
San Luis Obispo, California........ Whiten cs tale ates 170 93.68] 1.43 | 3.93 

Rio Puerco, Valencia County, New 
NIORICOS Soe sce thee ele oiteeiaen «eel ore TIGRE OTEEN acces + <% EIOc3 Tet as Grae’ ates 
New Pedrara, Lower California....|Faintly green........ 174.37} 90.16] 1.66 | 6.97 
as ae ~e+.»|White, rose tinted... .|173 93.48} 1.68 | 4.19 
a sh ene VV SLICE ares creat Seta cao eee 174 96.86) 0.24 | 2.79 
ay sd Porat Y WTOC. vs aso 174.37] 91.09] 0.64 | 7.49 
Neateiseiin vital racecourse cee a Vieliawaeast hows otra ere o7- 170 OP OT O.24an 
SLATES. 

* mf o*, | 2, s a 

3 ie erat ects ti ste cae 

Source. Q = Se on = og 

mS 3 © e: D a - = 

cs a alee Tee Bs os < 
Rutland County, Vt. (sea green)........ 65.02 16.02 5.44) 2.99] 2.00 | 4.16 
— ‘ie (unfading green)...| 64.71 7.84 Se AAme 7o23( 21 030120.02 
Sf (purple) as. caak 625.47 E3540.) 4521)” 7..06)°O.00)| 7720 
Granville, N. Y. (red)....... By eee Oe BE | SLO Hel 74e 106i tAtr 3 Oe 
Old; Bangor,) Penn: (dark) cscs see's» 0.5 56.97 26.05 ZOO 2631 
ibe F ONtie (OATK) ac ee ehaic c bebe s eee eS BS eTBK “secs 25.57|carbon| 2.10 | 4.00 
Peach Bottom Region, Penn. (dark).....| 58.37 | 21.98 | 10.66} 0.93} 1.20 | 1.93 











* These are the valuable constituents. ‘* Peroxide of iron is probably the coloring matter.”’, 


396 


BUILDING CONSTKUCTION. 


AIS, 


List OF IMPORTANT STONE BUILDINGS IN THE UNITED STATES. 


[Given to enable architects to see the appearance and weathering qualities of the 


different stones. *] 


GRANITE BUILDINGS. 








Locality of Quarries. Name of Building. 

Diselsland, Mee. 03.7... Post OMe oss. he co toa eae aie 
CN eS eo ne (New)! Post. Officer.) uate ere 
Hallowell’ Mé@i0. 05. es.a 02 State Canitolecu, o coe coeatast ee eee eine 
PN ob teil 5 Plc Ce KE 5° State Capitol | fii in ce Gan easa ode areas 

pe Re Ba is Equitsb'e Insurance Co. Building........ 

Cape Ann, Mass:...:.-...- Post OMeeers 2 ks ccuaiaee newt tue ee ae oe 
Milford, Mass>.......... Ciby, Hallet ace ache ce ic cnet toe nee 
Quincy, Mase. peau eee: U.S. Custom House. vet. e eee: 
BE re | Sevaletee st aistaretieteie Bunker: Bill Monuments... ccc era clas 

Se Fe Ain bopetens Weesata Post Office Srccdam cin coats a ete cen age 

£o wD Pilg gittanistacioen Aptor HOUSG son c ceca en ate re 

$F OAs Soheniaatis _.|Philadelphia National Bank........ Stas ine 

AO Seta antes Presbyterian, Chureh... 22 2. oen es sa eee eee 

OF Er swab eeern: Uss.Custonr House. 71s. s eet ees 

RED = Bee cow aapeates grote U; 8¢ Custom, Hous6atccn ss scscete ohn oe 
Concord, No Hiv w na. 00 Congressional library an. .seot. sees 
t Mie esos are State Capitol scien Saou oon pe eee ce 
Gunnison, Colo........... Stinte Capitol. 2 sco. - eee apn een 


Little Cottonwood Canon, 








City. 


New York City. 
Philadelphia, Pa. 
Albany, N. Y. 
Augusta, Me. 
Boston, Mass. 

(a9 


Albany, N. Y. 
Boston, Mass. 
Charlestown, Mass. 
Providence, R. I. 
New York City. 
Philadelphia. 
Savannah, Ga. 
Mobile, Ala. 

New Orleans, La. 
Washington, D. C. 
Concord, N. H. 
Denver, Colo. 

















Utalize eres cee tee Mormon Assembly House and Temple....|/Salt Lake City, Utah. 
LIMESTONE BUILDINGS. 

Locality of Quarries. Name of Building. City. 
LOCK POrty NA eee ace as Lenox | Libraryeer serene thes ects cee eee New York City. 
Bediord 2nd wae Aizonquin- Club Bullding <1 .s.seeceue ss. Boston, Mass. 

SE War ie th fox ah aweietts Residence cf Mr. Robert Goelet.......... Newport, R. I. 

Bee oe dah che, Shea ne aN Manhattan Life Insurance Building...... New York City. 

et eet ee ee Mail and Express Building............... e 

OOF asians Waar are American Fine Arts Society Building..... ‘ 

BE 7 od ion sae ea eens Residences of Cornelius Vanderbilt and ee (Fifth 

Weta Vanderbilt..9.05- eae Seneca ce Avenue). 

ee ae OR 2 ia ke Manufacturers’ Club Building............ Philadelphia, Pa. 

hn nt tet ote ‘(isa Baptist Church: aon secs kee es ce £6 

Pee er ort ae State Capitol vcs oy tats voces etme ene Indianapolis, Ind. 

ee ere Auditorium ybuiding yay c.nes seat eas ee Chicago, Ill. 

Se Pe nau nten oat LEEOU SSCA CION GG Con ec watts eaters eran eee St. Louis, Mo. 

Oe PA Ditch att at Cotton Exchange Building........<...... New Orleans, La. 

oat Be ee BiltmoOr@rcasese eth a totes cinae ca lane ee Biltmore, N. C. 
S@UNOM bya beets Cohen eee ae St. Paul Universalist Church............. Chicago, Il. 

Chains a euieeee cee Central Muse Hall a cee ot 
St) Paul Mintiicn.c....- Catholic: Cathedrals oe, .c.5erse oh come St. Paul, Minn. 
Kaostas Mint tess et coe Post: OUees scence caustic ema ey 
Bowling Green, Ky........ U. S.Custom ‘Tonuse, 22s fa eee eee Nashville, Tenn. 











* Some of these stones are used in a great many other buildings in the cities mentioned, the idea of 
the author being to give only one or two examples in each city. 





Locality of Quarries. 


tee eee eee eens 
tee e eee eee e ee eee 
Se a 
sence rene r ences 
oe © 2 S69" O' 6 6. G, © 6.8, 8)'8' 2 6 


Montgomery County, Pa. 


East Tennessee 
(74 


rd 
eee ewer eeos 
eee etre reese 
cere eee sees 
Se 
eee eee eoee es eeeaes 
ee ee 


Locality of Quarries. 


Longmeadow, Mass. (red 
stone) 
Longmeadow, Mass. 
stone) 
Portland, Conn. 
(brownstone). 
“ce 


Cr ee) 


eres eeree eres eee ee 


cc 


(3 be 
cc 
“cc 
ce 
“6 


“ 
“ce 
ii 
ce 
79 (9 
ce (a9 


Potsdam, N. Y. (red stone) 
6“ 6c 


6c ce 


Ohio Sandstone (buff stone) 
ce ce 


ee 


Portage Entry, Mich. (red 
stone) 
Fond du Lac, Minn. (red- 
dish brown stone) 
Kettle River, Minn........ 
Fort Collins, Colo. (dark 
TEC), BUGNG)Es vane cost ope 
Fort Collins, Colo. (dark 
Ted ‘SOONE he ag oes toe 2 
Fort Collins, Colo. (dark 
red stone) 
Manitou, Colo. (red stone). 


ee 





.|Girard College 


: eta (original) Buildin 
.-|Alumni 


..|Astor Library 
../Academy of Design (Montague Street).... 


..|Union League Club Building 
.|Residence of Geo. H. Pullman 


APP IGN DLX, 


TABLE C.—(Continued.) 


MARBLE BUILDINGS. 


Name of Building. 


(Old) Parker House, on School Street. ... 


St. Patrick’s Cathedral (in part) 
POGW. CLEY DS OUIGIN OB eh aciy cakes ec oo cece: 
Washington Monument (in part) 
Leo, Capwor Extension: fi cc.e co ate cs ss 
New York Life Insurance Building 
Hotel Vendome (new part) 


eeeeeneeee 
eee eee eee 


eee reese 
overseer eeeenees 


Coe eee eree eee eee see eeeeeesene 


Blackstone Memorial Library............ 
U.S. Custom House and Post Office 
U.S. Custom House and Post Office 
U.S. Custom House and Post Office 
Trimmings, Ames Building.............. 
St. John’s Episcopal Church 
aSTANtL CHDCrASETOUSC. ie wiciate wcic etre vas saat 
U. &. Custom House and Post Office 


eee eee es ese ras 


eee eee 


397 





City. 





Boston, Mass. 

New York City. 

Philadelphia, Pa. 

Washington, D. C. 
oe 


Boston, Mass. 
(79 


) Philadelphia, Pa. 
Branford, Conn. 
Knoxville, Tenn. 
Memphis, Tenn. 
Chattanooga, Tenn. 
Boston, Mass. 
Knoxville, Tenn. 
Atlanta, Ga. 
Jacksonville, Fla. 





SANDSTONE BUILDINGS. 


Name of Building. 


Trimmings, Trinity Church 


eres er eeeereeres 
core eee eee ee see 


eee eee eeeee 


all, Library and Art School, 
Yale College 


| 


..|Residences of Wm. H. Vanderbilt and 


Messrs. Twombly and Webb 


INFUISIG SEV a Saree ere ae cas chek eekis Cae 


eee een eosenese 


Savings Bank of Baltimore 
PaviiamMend Bushing esac ss es’ «mele six o's 
Cobre Bit COM GR Esc ccna -cis eaciol sats v/s 6) 0cn'0 de 
All Saints Cathedral 
Palmer House 
State Capitol 


State Mining School Buildings........... 


Westminster Presbyterian Church 
Board of Trade Building 


cee etree eee eee eens 


Grace Methodist Church 


Ce 


Union Pacific Depot 


eee reer eee reese rsereeree 


American Exchange Bank 





Boston Building 


Ce 


City. 





Boston, Mass. 
Chicago, Il. 
Boston, Mass. 


Hartford, Conn. 
New York City (Fifth 
Avenue). 
New York City. 
Brooklyn, N. Y. 
Buffalo, N. Y. 
Philadelphia, Pa. 
Chicago, Ill. 
Baltimore, Md. 
Ottawa, Ont. 
New York City. 
Albany, N. Y. 
Chicago, Ill. 
Lansing, Mich. 


Houghton, Mich. 


Minneapolis, Minn. 
West Superior, Wis. 


Denver, Colo. 
Cheyenne, Wy. 


Kansas City, Mo. 
Denver, Colo. 








398 


TABLE D. 


BUILDING CONSTRUCTION. 


THE EFFECT OF HEAT ON VARIOUS BUILDING STONES.* 





Kind. Locality. 
Light colored granite....... Hallowell, Mes... .:..cs ace 
LEC. OTANItE Se he cactis ces beers Starks NeH oe cees cose 
Carter’s Quarry granite... s\|Woodbury, iit. 51 «1 o0 stereis 
Py enite et cds ea wen eee Quincy, Masse cetec sce. 
Common granite... ....... Woodstock, Md... c.....=0 
O]d Dominion Quarry gran- 

GCE Ro eee ae oe eee Richmond; Ware.es eee oe 
Light colored granite....... St. Cloud) Minn eases sees: 
Sandstone . :.sc.ss+.0ceece- Portland, ‘Conn aS Piiriey, Arar 
HaAndstONne-6 a. % seve oc seers Seneca, Md,o0 eke. tate: 
Sandstone -ac.creesccscemes INGVaiScotiatca-mucnnose ume 
Potsdam sandstone........ McBride’s Corners, O...... 
Berca sandstone........... BereaO oe oi eee 
Limestone.. ........ Selects Baltimore, Md jaecsssccines 
Limestone: 4.<--osene cers Bedfords indwer-coet onto 
Cincinnati limestone. Hamilton county, O....... 
Potts’ blue limestone...... Springfield, Penn.......... 
Dolomite limestone........ Owen Sound, P. O..... STs 
Trenton limestone......... Montreal Bii@ iacasiess es 
Limestone: oe un eee ene Isle La Motte, Vt........... 
Tuckahoe marble.......... Westchester County, N. Y. 
Ashley Falls marble....... Ashley Falls, N. Y...- ; 
Snowflake marble........... Westchester County, N. vs, 
Tennessee marble.......... Dougherty’s Quarry, East 

Tennessee.. —.....- + se 
Duke marble: so .s<se<teos5s- Near Harper's Ferry, Va... 
Black marblewczs 2 as -n eee- Isle La Motte, Vt.......... 
Sutherland Falls marble...|Rutland, Vt ............... 
Conglomerate.... ......... Roxbury, Masses... os oe. 
Potomac stone............. Point of ?}ocks, Md ....... 
Conglomerate.... ......... Caps a La Aisle, P. Q...... 
Artificial stone...........-. McMurtire and Chamber- 


lain Patent 


Cr ee 


foot in pounds. 
Ratio of 
absorption. 
First appearance 
of injury. De- 


| Weight per cubic 


164.8 


1-320 
1-340 
1-320 
1-342 
1-49 





170 2)1-60 
165 .3|1-80 


39.7) 1-280 








grees F. 
First appearance 
of cracking or 


crumbling. De- 





950 


950 
1,000 
1.000 
1,000 

700 

600 

600 


750 








grees F, 
General crackin 





800 


£ 
Deg. F. 
Melted or de- 


grees F. 


Degrees F. 
stroyed. De- 


less. 


Rendered worth- 


and friability. 


| 





950) 
800 
950 
80 
800 


850 
800 
950 
1,100 
1,000 
900 
950 
1,100 
at ‘000 
950 
900 
1,100 
* 1.000 
1,100 
1,200 


aa 


wor 





(Sieatp, 
S388 
SSsss 





1,100 
1,000 


1,000 
1,100) 1,200 
1,100 
1.100 
900 
800 
$00} 900 


1,100) 1,200 








eeeoe 


* From ‘ Notes on Building Stones,” by Dr. Hiram Cutting, Montpelier, Vt., 1889. 


‘‘ The experience of the citizens of North Arkansas is that marble is much su,erior t che sandstone 
in withstanding heat, and because of this fact, where chimneys are built of saudatone tpe irepiaves are 


lined with marble.”’ 


. 


= 


399 


‘ 


APPENDIX. 












































‘a9dpo UO PIV] SHG a *gasinood g Al9AO TAYOIq SsJUIOL P 
8°06 ].O°TLT | Ste'e | O00'FE { O0O0'0SG | 00'FFT 9°96I ‘quauI9 PUBTWOd WON( VT | ef | O 9 
LST | OGL | BLT | OOO'SSS | 000‘08G | 00'FFT LOU _ ‘pussg » »| OL ra 0 9 
FSI | M9 IOL | TIFT |. 006'S0G | OOOfOST | 00°FFI S081 ‘1eq10Ul ATT { “GUOTUGD PULT}IOd [| BL él OFP59 
SLL | OGL | GLGL ; OOOFSE | 000°096 | 00'FFI 0'S61 ‘puRs gy» »| 6 at 0 9 
BFL | “SIT | OFY'T | OOO'LES | O00‘O9T | 00'FFT 9 OGL ‘1BJ1OU OUI] G ‘UWI B[VpUESOY 1] ST rat eas) 
904 | SAS | TIT | OOSEST | OOO'OIT | Se°9ST LSI ” »| 6L ae Open 
AIL | s'c6 | Test | 009°16L | 000°08 00°FFI @'SI1 ‘puss ¢ ‘OMIT [| BT ol 0 9°P 
‘(ALVIS AV) SMOINA NOWWOO JO LINE 
“SOTOUI CL*FXCL'F 9100 MOT[OT SBFT 9 *SOqOUl [FX] 'F 9100 MOT[OY SBH Q *SOTOUI CE PFXKCG’F 0100 MOTION SvyT V 
SOL | SSSI | 288'T | OOL'SSh | O000FE | 00°92 » »| OL 91 0 OL 
SFI | SS6L | 02'S | 000'969 | 000°09F | 00°9S6 Fee »| OL 91 Soa G 
GOL | S FFI | 00% | O09!92@ 90°88 O'IST ‘pus g “quomed puvlyog [| SI ral 0 OL 
98 | SPIT | 48G°T | O0S'S8T | 000/02 OS’ SLT 0°98 ” »| GL el 0 O19 
['9 | S08 | SILT | OOS'FST | 000/02 90°88 CISL ” »| SL ol 6.7.6 
LIT | S'FST | OST*S | OOF'96G | 000'SL 90°8&T ” »| SL rat 0258 
B'S | SOIT | OFST | 001/96 OF 69 9° SST Pe Sith Pas 8 Saag 
SSI | 9'GLT | OFF'S | O0S*SFT | 000°99 08°09 9°SET ‘puss g ‘oul, Tl 8 8 yas al 
‘(SANVS °M ‘W) SHOIUM NOWWOO JO LTING 
GOI | V's9T | Scs's | 000'86G | 000'00G | ss'eET ciel | 9 Tass oi oa 0 or 
£96 | G'F9G | 09'S | OOO'OSF | 00N'00G | Ls'eET ‘pues g ‘yuomes puRiyog 1] GT ol 0 & 
OSL | LOST | LOST | 009'806 | OOO'OOT | FF'SIT 0°S6I1 ” »| SL ral 0 Oo1@ 
GOL | SSO | TLS*T | OOS‘66T | O000'0L CBSEL LTS ” »| SL re A 0 OL 
SFL | SFI | OGG'T | OOL'9GB | 000'06 QL°SIT ” » | OT ra Ws ake 
GEL | LEST | OFET | OOL'ZGS | OOO'OFL | 6°CST ‘pues ¢ ‘omy [| SI rae We te 
GOT | G IGT | 6FGG | 0066S | 000'S8 QL LG G'SeT ” 31-8 8 8 9 
LLG | S'IL4s.| 9LL'S | OOL'SIS | 000/008 | 9L'LS $981 ‘puss g ‘JUSTO. puL]WOg T| 8 8 Fak 
GSI | LCST | LL8'T | OOF‘SOL | 000'0¢ 9L°LG G'S : %9 »| 8 8 gs 9 
U'Sl | #I8t | oss's | OO09‘EFT | 000‘SS 00°LE FLST ‘puss ¢ ‘oul, [| § 8 ro ae 
‘SLO | “SAI ‘Sa "Sq ‘Sql “uy ‘Ul ‘Ul. 
CIEL wey ep eran ae 
ergurs | “PS | “Ul ‘1R10L Serra ‘UOT}OOS-SSOID | “GYSIOH 
jo» | td Hd. oi ea ta ‘wore | 4 ee “1By10U1 JO UOTysod WOH 








qsilq | TeuOTIpg 
“‘qysuad4s 9yBUITITD 7U510 M ‘SUOISUDMIG] [BULWON 











‘SHINON FZ OL QT “ADV ‘(SSVIN ‘HOGIUANVO ‘SANVS “M ‘N) SHOINA-AOVA JO LIINA 
‘SVJ ‘NMOLYUGTLVAA LY LNAWNYAAOD ‘§ ‘f) FHL AX ACVW SUAIG WOU JO HLONTALY ONIHSAAD IVALOV AHL dO SLTAsAY aagLvInavy 


‘d WTaVe 


400 BUILDING CONSTRUCTION. 


A Bite re: 
SAFE WORKING LOADS FOR MASONRY. 


(From the Architects’ and Builders’ Pocket Book.) 


BRICKWORK IN WALLS OR PIERS. 


Tons per square foot. Eastern Western 

Red brick in lime mortar............ Bt acauer a coe cee aad A At hire eee, 5 
ss hydraulic lime mortar.......... Sereda tis ets eae Sart aoank Meese 6 

ie natural.cement mortar’ £s(0°350 vse vata an he ks hie eiate seme BO 8 
Arch or pressed brick in lime mortar iba saute eta elt pia Oi nlaleve Nisin vis Rte ana stig 6 
ne vty natural Cementsick s vce scr'ele vic giamtennies = ate eiaiaeteeh Rane o 9 

~ 4 ao Portland cement, s'-. = «<0 «0% sss sysuerinio's 6 ere een ntey uote 124 


Piers exceeding in height six times their least dimensions should be increased 4 inches in 
size for each addititional 6 feet. 


STONEWORK. 


(Tons per square foot.) 


Rubble‘walls, trrepular:stonessv. vcs ae wes 0s ennerses iva ces gseciee mma aie soe em 3 
#e coursed SOL -StONE ss! ios acd fe oh eee cosas Heat outa ee cae ee ate 2t 
ae id hard SLOMECE ou eus aatercteielciciers eels eheve ereteleletate ate ererehenenersvereiers 5 to 16 


Dimension stone, squared in cement: 


Sandstone and limestone....... hy aera bie Hp\s Sos bis Saisie os waite kas wom ea a eieteis eee COED 

Gramtewnn as. eos oe Sie-e © Rpeiohe a eietaih wie'e Oe Sle edt w Soemeate Wieldile aie iel enue eile weteielciets © Stem SUE ORAG 
Dressed stone, with 2-inch dressed joints in cement : 

CSPATITCG a og is ae ectets Beara eee Sieg mis quad bp walevacente Sis prea be aiid atel a tietstecs 60 

Marble. or limestone: Dests, 24s «ts d'sea ce sho are giete Palate ois sccm wale = eee a ane e ci alate 4o 

Sandstone.. eeeeoe eeoevoeeece*eeven @ eeeeeveeveeeee7 ee Cpe eeee eee eevee sveeeeeeeevee oe 30 


Height of columns not to exceed eight times least diameter. 


CONCRETE. 
Portland iéement;- Tito’ S207 oe ssw ois bee wae Se ok Pele eee oe elec es Ob oe ets see LOMeO 


Rosendale cement, I to Oey eG aN ORR Bie nt one gtr hdd Ayia EAI Pa eeenveen sd 5 to Io 
Hydraulic lime, best, THO IO. Caled cake Gee ele wees Me CaS ee bes eee a Ce cb aie eae aes 5 


HOLLOW TILE. 


(Safe loads per square inch of effective bearing parts.) 
Hardifite-clay files pact fc os ce aoa Vig ca how's.n Sats ohn oh bing lus vimmnaiar eteta nie ew 'ele wie thereat ae 
es -OFGINATY CHAY THES oy eics'< ato este ee < Xo Seek > aoe SON Sve @ dug ota Beeealenale Cree eT REE 
Porous tetra: Cotta’ tiles. 75 siys cdiels 5 oe ois tie alten g's es ti0ls 0 ones nS oles ere by ie eeeeieee mee meee 


MORTARS. 


(In }4-inch joints, 3 months old, tons per square foot.) 


Portland, centént, 1° t6. 4ecy <xs 5 <4 s'e b's a's 0 sew weet oa ae eee ae eta ee tee eee 40 
Rosendale cement, 10 Fic o.c usccee sv ay oe s'iny's od wie o ausietaye opaleteleremiars ts eta Spe Sata ame 13 
Lime-imertar, bests.2 cc se ease cath oes cole ee eee a cha Fate ca Ue gure’ Medien se ee tdle Ange syarereaishe sO EORLO 
Best Portland cement, I to 2, in 4-inch joints for bedding iron plates............ 70 


*“* The concrete and twisted iron columns in the Pacific Coast Borax Works, 16 inches in diameter 
and 1: feet high, are habitually loaded with about ;6 tons to the square foot.”—Z. L. Ransome. 


— 


APPENDIX. 401 


TABLE G. 
PROPERTIES OF TIMBER, STONES, IRON AND STEEL. 


(Values for strength are those given in the Architects’ and Builders’ Pocket Book.) 






































ol a 

o o 
aS a; ui ba : s : = ioe is al Go A 
com oO gS WES |o Ss op We BO] Om YO 
Be May) bs | Se IS FS See SE RES 
) ) nes Ch om Rid 5 ~ baal ett me 
pA aS Ao | Bao Rae ge zo kas 
Oa Sal » & Sanu oe|e Sea Ss ea 8 
RAPS Se | Fig (Vesa = aa ka oe 
eo bie" 8132.) 5s8 BF she 2254 28 
cose a) 5 2 Oo ton [OM Wl) o OOS Alo ten F 
on Ss © we wa 8 we Wa 2 
LO D EY eB i) Bey Sor HI a Ae 4g, 
eal Se een Be oe (AO, Bt st 

= at ee Asa %| a A 

nn 

NETPESE rere wine stuido eae etsistee.e os 4o Pe 1,500 530 | 60} es, ies 
TLGii loc keer sens os tivaaence| 41 G0 2.5 1,200 450 | 55 70 200 
Oak white (ss. auto eee st ae Bo 4.3 | 2,000 TKO eae I 150 600 
Pine, Georgia yellow,. «0s... *| 43 3.6 | 2,000] 1,000 |100 120 500 
Pine, .Orevon Wiens aegis ieee 1 30 a 1,800 750 | 90 + 100 400 
Pines Norway. wesc ees wee Ale te 3 1,600 700 | 70 300 400 
Pine, white Western ...... cei ae gO 2.5 1,500 625 | 65 80 200 
Reagwi0dee ere wastes icems seu Af he 800 600 | 60 70 175 
Spruceei.w sks cst tees 4/8 0,6 ea 2S 3 1,800 625 | 70 go 250 
WHHEWOOU Gaacieeceicccaeeacteh 235 3 1,200 500 65 | vance 200 
SIATOs saree ia eo uteh ais, oad are 174 a aoe Py ceva tae pies ara 
Bluestone: fageing. i... ..5 0 ere i ari see of eS Solas weiss 
Cranile selpete, Sew Senn dave © a8 167 ae avers 850 | 18 eke bh ate 
Limestone (Inds). Weitn..c. 00s s| 158 " aah £50 | 18 reir e ones 
Marbles-oee.. . sleche macs he ae 170 ‘6 Cates 550 | 18 sila 'aare eles 
Sandstone Mock «cis caters te elec" 139 a ts 450 | 12 ve: woe 
Cash roles ee wicale cfc ates Rete ey UP Ke) ce 2,600} 13,500 |308 7,000 earns 
Wrought irOn, wa. ese «4 64e 9. 480 os 10,000) 10,000 |666 7,500 12,000 
Steel; medium.cs.2s0 ec. ss» «| 400 .. |12,500} 13,000 |888 7,500 12,000 
: PINS tone he ha ost es te see 3 ere Ore 7,500 12,000 
i Pivetsi sos eek ie Ah Phe at: ba rected ke 7,500 15,000 





* One-eighteenth of the ‘‘ fibre strain’ or safe ‘* Modulus of Rupture.” 
+ Vor full permanent loads, such as brick walls, etc., use only four-fifths of these values. 


MAKING CELLARS WATERPROOF. 


Quite often in cities it is desirable to construct a dry basement in local- 
ities where water permeates the soil to within a few feet of the sidewalk. 

In such cases it is necessary not only to make the walls and floor water- 
proof, but also to give sufficient thickness to the floor that the buoyant 
force of the water will not cause it to break through. 

To make the cellar water-tight the entire area of the cellar should Le 
covered with concrete, after the footings of the walls and piers are in, from 
3 to 6 inches thick, so that the concrete will be level with the top of the 
footings. A narrow course of brick or stone should then be laid along the 
centre of the footings, as shown in Fig. 249, to form a break. Upon the 
top of the footings three thicknesses of tarred felt or burlap should then 
be mopped in hot asphalt, the felt being allowed to project 6 inches on 


402 BUILDING CONSTRUCTION. 


each side. A similar layer of felt and asphalt should be laid over the 
footings of all piers, engine foundations, etc., and allowed to project at 
least 6 inches on all sides. 

After the external walls are completed, and before “filling in,” the pro- 
jecting felting should be turned up and mopped with hot asphalt against 
the wall, and the entire outside surface of the wall to the sidewalk line 
covered with three thicknesses of felt laid breaking joints in hot asphalt and 
overlapping the felt that comes through the wall. For further protection 
this covering is also frequently plastered with 1 to 2 Portland cement 
mortar. 

Before the completion of the building the entire cellar floor must also be 
covered with felt in hot asphalt, laid in at least three thicknesses, breaking 
joint and overlapping the felt first laid. 
On the top of the felt thus laid there 
should then be laid Portland cement 
concrete at least 1 inch thick for each 
3 inches in depth of the water above 
the level of the cellar bottom, with a 
minimum depth of 6 inches. 

The following description of the 
waterproofing of the basement of the 
Herald Building, in New York City, is 
given as an actual example of the 
above method :* 

In this building the printing presses are 
placed in the basement, and great pains were 
taken to exclude moisture below grade. The 
footings and outside basement walls were covered with four-ply burlap mopped on solid, 
commencing at the inner edge of sidewalk and back over top of vault and down the outside 
of the wall to the bottom of the same, thence through the wall and turned up against same 
for connection to the waterproof course. 

Beneath the surface of the entire basement, including floor of vaults, the best four-ply 
roofing felt was mopped on solid, and similar material was used in connection with all 
piers, extending in each case through the entire thickness of ‘the pier and beneath the 
entire surface of foundations for boilers and machinery. 


The felt was securely lapped and turned up around all walls. Above the felt 4 inches 
of concrete was laid in the basement and 16 inches in the boiler room. 





If less expensive, hard bricks laid in cement mortar and at least three 
courses in thickness, may be used instead of the concrete above the felt. 


*From the Engineering Record, July 1, 1893. 


APPENDIX. 404 


STAIN AND DAMP-PROOFING.—ANTIHYDRINE. 


In Section 301 attention has been called to the frequent staining of 
plastering applied on fireproof tiling, which has proved a source of 
much trouble in getting a fine decorative surface, the stains showing 
even through oil paint. 

Similar trouble is also sometimes experienced with plastering ap- 
plied directly to the brickwork of outside walls, so that any prepara- 
tion which will prevent these stains is very desirable and should be 
known to all architects. In Section 301 an English preparation, 
known as Duresco, is recommended for this purpose, but the author 
is informed that this material is not now carried in stock in this 
country. 

A new preparation called Antihydrine is now made in this coun- 
try, however, which appears to be an excellent article both for pre- 
venting the stains in plastering due to the mason work and for damp- 
proofing, and seems to have given excellent satisfaction. 


Antihydrine is a high grade of ashphalt varnish, which can be ap- 
plied cold to any porous surface without being absorbed by the ma- 
terial or becoming too thick in places. It is said to absolutely pre- 
vent the passage of moisture, which is generally admitted to be the 
agent which produces the stains in the plastering. 


To prevent the staining of plastering it should be applied with a 
brush directly to the inside surface of the mason work, whether the 
latter be brick, stone or fireproof tiling. But one coat is required. 

About twenty-four hours after the Antihydrine is applied, and 
while it is still soft, the plastering should be applied in the usual way. 
It has been found that plastering adheres to this coating equally as 
well as to brickwork, and that it dries much more quickly and evenly, 
and that decorating can be’safely applied within a few days after the 
last coat of plaster is dry. 

As the Antihydrine absolutely prevents the passage of moisture, 
furring the walls can be safely omitted, thereby effecting a saving in 
cost and in the thickness of the walls, and also, it is claimed, in the 
time required for drying the plastering. 

Mr. Louis De Coppet Berg, of Cady, Berg & See, architects, states 
that his firm now omits furrings entirely, covering the wall instead 
with Antihydrine, and that they also cover all fireproof surfaces of 
partitions, ceilings, etc., with this material before plastering. 

It has also been found to be an excellent base for whitewash, the 
second coat drying out perfectly white and free from stains. 


4o4 BUILDING CONSTRUCTION. 


When used under whitewash, however, the Antihydrine should be 
allowed to harden thoroughly before applying the whitewash, and at 
least two coats of the latter should be applied. 


Antihydrine is also recommended for coating the built-in surfaces 
of limestone and marble, as it prevents the staining of the stone by 
the mortar. When this material is used common mortar may be used 
for laying the backing. 


The manufacturers also state that they have found this preparation 
an excellent material for priming the outside of brick walls that are 
to be painted, as it takes the paint perfectly, and two coats of paint 
over one coat of Antihydrine makes a perfect job that will not peel 
or crack off. 


The material is quite inexpensive. 


Mr. Berg states that plastering that has already become stained 
cannot be improved by applying Antihydrine to its surface, it being 
‘ necessary to apply the Antihydrine to the wall defore plastering. 


THE ROEBLING FIREPROOF FLOOR, 
Additional Data Relative to Weight and Strength.— 


On page 290 is given the actual weight of various systems of fireproof 
floor construction when built between 
12-inch beams. The concrete used in 
the Roebling floor in this test had 
broken stone aggregate. In nearly all 
buildings where this construction is 
used, however, thc concrete is made of 
cement, sand and steam ashes or cin- 
ders, which greatly decreases the 
weight. The following table gives the 
average weight per square foot for 
floors constructed of concrete mixed 
in the proportion of 1 part Portland 
cement) (2) Oletsand). and) 5 sOmwcin- 
a = ule ders, the weights being based upon 
ee results obtained by weighing the 
ak yen yen eb materials taken from sections of 12 
Fig. 250. and 15-inch levels two months old 
and perfectly dry. Of course when 

first laid they will exceed these weights. , 
The table also gives the maximum spacing of floor beams for 











APPENDIX. 405 


different heights of arches, measured from under side of beam to 
top of arch. 





WHEN CONCRETE IS |MAXIMUM SPACING 














TO BE LEVELED OF IRON FLOOR THICKNESS OF WEIGHT PER SQUARE 
ABOVE UNDER BEAMS (IN DE- Y FOOT, INCLUDING 
SIDE OF FLOOR PENDENT OF SIZE pes ie Leu ONLY CONCRETE 
BEAMS TO A OF BEAMS)SHOULD. oa he tee AND WIRE. 
HEIGHT OF NOT EXCEED 
8 inches, 4 feet o inches. 3 inches, 28 pounds, 
9 oe 4 oe 6 of 3 6é 30 ae 
ZO ce cas O “e cc sé 
12 “e 5 ae oO cc : cé 5 66 
I «sé eé 6 ce «ce eé 
5 7 3 53 








In spans of over 5 feet allow 14 inches clear rise for each foot of 
span. ‘The weights given are for concrete to level indicated in first 
column, with 3-inch crown, and for all wire construction, including 
arch wire for floors and lathing for ceiling. Add for plaster 8 to ro 
pounds per square foot. Weight of structural iron and of wood or 
other finished floor must also be added for total dead load of floors. 


All floor beams should be tied together at intervals of about eight 
times their depth, and should be framed level and flush on the un- 
der side where flat ceilings are desired. 


The ceiling, when plastered, finishes about 13 inches below the 
lower flange of floor beams. 


Test of Strength and Resistance to Fire.—As the great strength and 
fire-resisting qualities of concrete arches do not yet appear to be 
generally appreciated, the following report of a severe test of an arch 
built on the Roebling system is given for the benefit of any who may 
yet be skeptical on the subject, the description and illustration being 
taken from the Angineering News of February 4, 1897: 


The floor arches shown in section in Fig. 250 were concreted on September 26, 
1896, and on October 28 the fire test was made. The floor was loaded uniformly 
with 150 pounds to the square foot, and at 10 A. M. fires were lighted on the grates 
beneath the floor. The temperature on the under side of the floor was maintained 
at above 2,000° F. for three hours, and at 3 P. M. a powerful stream from a fire 
engine was thrown against the under side of the floor, which was at the time so hot 
as to glow. 

After the floor cooled, on the following day, the load on the floor was increased 
to 600 pounds per square foot, still without signs of failure. 

On December 11, 12 and 14 a section of one floor arch, 2 feet 6 inches long and 
4 feet span, was isolated from the rest of the floor by cutting openings in the con- 
crete from beam to beam on each side. Upon this was built a brick pier 2 feet 6 


406. BUILDING CONSTR OCCLION, 


inches square and a foot high, and upon this pier was placed a platform of plank 7} 
feet square. This was then loaded with brick and stone, as shown in the figure until a 
weight of 40,000 pounds had accumulated and the pile became so top-heavy that 
further additions were deemed unsafe. The deflection of the arch under this load 
was I inch, and after the load was removed this was decreased to 8 inch. 


The concrete in this arch was composed of 1 part Aalborg Port- 
land cement, 2 parts sand and 5 parts steam cinders. 


THE-EXPANDED METAL SYSTEMS OF FLOOR 
CONSTRUCTION. 


The use of expanded metal in combination with concrete for floo1 
construction has become so extensive that a description of the more 
common methods of using it may be considered as necessary to 
complete the subject of fireproof floor construction. 

Two primary methods of construction are employed, the adoption 
of the one or the other depending upon the character of the build- 
ing, the purpose for which it is to be used and the form of ceiling 






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desired. In one of these methods, illustrated by Nos. 3, 5 and 8 
Fig. 252, the floor is constructed as a composite slab, on the same 
principle as the Ransome floors, the expanded metal forming the 
tension member. In the other method the arch principle is em- 
loyed, the expanded metal being used as a centre for the concrete. 
The expanded metal used in floor construction is made by the same 
process as the expanded lath, but of heavier metal, usually from 
Nos. ro to 16, and of either 3-inch or 4-inch mesh, the appearance of 


APPENDIX. 407 


the floor material being as shown in Fig. 251, which is about one- 
quarter size. 

Fig. 252 shows four styles of flooring which have been found best 
adapted to the usual requirements. The spans indicated are those 
which are usually the most economical, but they can be varied to 
suit the divisions of the building. 

Systems 3 and 5 are most commonly used in office buildings, 


ESAS Th EER OLE ROIS CATO) MAGES CESS TT GA 
se At z ose F a oe : 





No. 8.—Span, 4 feet ; weight, 35 lbs. per sq. foot. 





No. 9.—Span, 6 feet ; weight, 45 lbs. per sq. foot. 


Fig. 252. 


hotels, etc. Where the rooms are uniformly arranged, with the par- 
titions placed under one of the beams, system No. 5 may be used 
to advantage, and a considerable saving in the height of the building 
effected, as only about 5 inches of this height is taken up by the 
floor. 

No. 8 is especially adapted to light floor loads such as are usually 
found in dwellings, apartment houses, etc., and where the beams do 
not need to be very heavy. 

No. g is constructed by springing sheets of expanded metal be-. 


408 BOLE DINGS CONST 5 OCLTON 


tween the floor beams and filling on top with concrete composed of 
Portland cement, sand and steam cinders. It 1s adapted to the heav- 
iest loads and to spans of from 6 to 7 feet, or so that 8-foot sheets 
may be used for the arches. 

The thickness of the floor slabs is usually about 3 inches, and of 
the arch at the crown from 2} to 3 inches. The weights given are 
exclusive of the beams and wood or tile flooring. 

Repeated tests have demonstrated that either of the flat systems 
have abundant strength for the ordinary loads in office buildings, 
apartments, etc., and the arch system may be safely used for the 
heaviest warehouses: The tests have also shown that when over- 
loaded, such floors do not fail suddenly, but quite gradually, thus 
giving warning of their dangerous condition. 


TERRAVBUANCATEIREPROOTS LIEUING. 


This is a fireproof material composed of silicates, alkalies, iron and 
gypsum, mixed with cinders and slag from blast furnaces. 

It resembles in its appearance the various compositions of plaster 
that have been placed on the market, but the author believes that it 
is superior to them in its fire and water-resisting qualities. 

The material is probably not surpassed even by porous terra cotta as 
anon-conductor of heat, and it does not appear to be greatly injured 
by intense heat, although, like all plastic materials, the surface soft- 
ens by recalcining and also upon the application of water. 

Terra Blanca is remarkably light in weight, and for this reason is 
well adapted for partitions and for ceilings under wooden joists. It 
is a non-conductor of sound; plastering dries on it very quickly, and 
it is inexpensive and easily put up. It is not capable of sustaining 
heavy weights, and should not be used for bearing partitions, but 
there are many places where, in the opinion of the author, it could be 
used to good advantage, especially in lessening the fire risks in 
wooden buildings and in making them more sound and vermin-proof. 
It is also used for fireproofing steel construction. 

Although but very recently placed on the market, Terra Blanca has 
been used in several notable buildings in Chicago and in numerous 
buildings elsewhere. 

It is moulded into slabs from 1 to 2 inches in thickness, 134 inches 
wide and 48 inches long; these slabs can be applied to wooden stud- 
ding or floor beams, or to brick walls, by means of capped wire nails. 

The partition slabs are made of the shape shown in Fig. 253 and 
3, 4, 5 and 6 inches in thickness. These partition tile can be laid up 


APPENDIX. 409 


without mortar, small steel rods being used for holding them in place, 
as shown in Detail A, or they may be set in mortar and the rods 
omitted. 






i: DETAIL A 


Fig. 253. 


Nails can be driven into the tiles without breaking or chipping, and 
the tiles can also be readily cut with a saw. ‘The manner of applying 
the tiles and slabs to wooden buildings is also shown in Fig. 253. 


410 BUILDING. CONSTRUCTION. 


The weight per square foot of the 1-inch slabs is 4 pounds, of the 
3-Inch partition tile, 9 pounds; of the 4-inch, 11 pounds; of the 
5 inch, 12 pounds, and of the 6-inch, 15 pounds. A partition of 
4-inch tiles, with two light coats of plaster on each side, will not 
much exceed in weight an ordinary lath and plastered partition with 
2x4-inch studding. 


PELTON’S SYSTEM OF RELEASED WALL FACING. 


During the past four years .(1892-1896) Mr. John Cotter Pelton, 
architect, has developed and patented a system of released wall fac- 
ing which has met with commendation from many prominent archi- 
tects, and which the author believes to be sufficiently practicable as 
to interest all architects and students. The essential feature of this 
invention 1s the idea of supporting a costly facing of stone, marble or 
terra cotta from a wall of common masonry, or from a steel frame by 
means of metal anchors and brackets, which hold the facing away 
from the wall or frame and also permit of its being set after the sup- 
porting wall is completed. ‘The general prnciple of construction is 
quite clearly indicated by Fig. 254. 

The advantages claimed for this system are: First, economy of 
material in the facing; second, saving in time required to complete 
the building ready for occupancy; third, protection against the pen- 
etration of moisture; fourth, elimination of the bad effects of settle- 
ment 1n the walls and the staining of the facing from the backing; 
fifth, protection against exterior fire. Of these advantages the first 
and second will probably have the most influence in extending the 
use of the system, as they have a direct bearing upon the cost and 
financial returns of the building. The other advantages, however, 
are perhaps the most important from a constructive standpoint. 

As the facing is treated merely as an external covering, principally 
for architectural effect, and has nothing to support, it can be made 
very thin, thus permitting the use of expensive materials, which, 
with the ordinary method of construction, would be prohibited on 
account of the cost. | 

The anchors which support the facing being built into the sup- 
porting wall as it progresses, the facing can be applied after the roof 
is on and while the building is being finished on the inside, or even 
after the building is occupied. Hence a building faced with marble 
under this system could be completed ready for occupancy in about 
the same time that would be required if the walls were of plain brick- 
work, and ample time allowed for cutting and setting the facing, and 


APPENDIX. 4IT 


even for quarrying the stone. In fact, any unavoidable delays with 
the stonework, such as strikes, unfavorable weather, etc., need not 
delay the finishing of the interior of the building. 

As a protection from dampness the advantage of this system is 
obvious, as a continuous air space is provided between the facing 
and the supporting wall, with only the metal anchors connecting the 
two. 

The facing being applied after the supporting wall is completed, 
all settlement in the latter will have taken place before the orna: 








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af 1 


ma : 

Ea CeESSn el 

eae El 

lara w SAL 
EE zs ; shel ote TEENS . 








TT 





Detail of Anchors. 


Fig. 254. 


mental work is set, thus avoiding the cracks which frequently occur 
in facings that are bonded into a brick backing. Of course any set- 
tlement in the foundations would affect the facing as well as the sup- 
porting wall. A facing supported in this way will also serve, while 
it endures, to protect the supporting wall from external fires, and 
should a portion or all of the facing be injured beyond repair, it can 
be removed and new pieces subs‘ituted. A facing of either marble 


412 BOLL DING CONSTRUCTION. 


or limestone would probably protect the structural wall from serious 
damage from any ordinary fire; and even when the fire is inside the 
building this method of facing is likely to prove an advantage, as in 
such cases the flames generally destroy the stonework around the 
exterior doors and windows, and with a released facing the injured 
stones could be replaced if the structural wall was not weakened. 

This system of construction has been adopted in a few buildings in 
California, of which the Public Library at Stockton, a building 
in the Renaissance style and designed by Mr. Pelton, is the most 
elaborate. 

“This building stands on a corner and has exposed about 210 feet 
of frontage, the whole of which is of white marble on a light gray 
granite foundation wall 7 feet high. The structural walls are of 
brick, 24 inches in thickness, and the ashlar is 2} inches thick, with 
an air space of 23 inches. The whole of the work on this building, 
except the finishing coat of plaster and the interior woodwork, was 
completed before the marble for the facade was delivered upon the 
ground. ‘The whole cost of the exterior marble work was less than 
$17,000, in which is included not less than $3,000 for carving and 
the cost of six monolithic columns 16 feet in height.” 


The anchors or carriers in this building were all set and adjusted 
by an engineer, so as to secure perfect alignment, and no difficulty 
appears to. have been encountered in any portion of the work, 
the appearance of the building on completion being the same as if 
constructed in the ordinary way. 


“ At one time during the progress of the work there were men at 
work at not less than five different parts of the building and on 
eight different levels. 


*“‘ Every stone sent to the staging as correct in size was set without 
trimming; in fact, fitting and trimming were not known upon the 
staging. ‘The only cutting known to have been done in the work of 
setting was the small amount of channeling required for the carriers, 
and this work hardly occupied the time of one workman.” 


The shape and size of the carriers or anchors will necessarily de- 
pend a good deal upon the size and weight of the pieces to be sup- 
ported. The shape of some of the carriers used in the Stockton Li- 
brary is shown in Fig. 254. To insure the successful setting of the 
facing the carriers must be set with great exactness, and Mr. Pelton 
recommends that an engineer be employed to give both the horizon- 
tal and plumb lines. 


APPENDIX. 413 


The window frames should be set before the facing and the latter 
built around them. . 


As stated in the first paragraph, this system of construction has 
been patented by Mr. Pelton, and architects who wish to adopt it 
should consult with him in regard to royalty, details of the carriers, 
etc, 


INDEX TO ADDITIONS. 


[SECOND EDITION. ] 


Antihydrine damp-proofing matérial.’.0.'1s vase eher ere erdeee eet me 403 


Brick fireplaces irs siicevithects sis wegen oo artete abciein are sae ates cat ements tigietc teen tad 242a 
Brick spiral (stairs 2 vs:vivnla dicivigs ae 0 tiara earn eokenie acne sre ikis Wickens ree eae 2425 
Colored sandwitnishcs, seutne tee ees ies etait We deze ci isk ig or Glan sar aveys donee eae © 356 
Concrete Steps) Se. ite. dey ares ace ol cee aeons a maaan Rete CRP ere cece tie 36924 
Door and window frames in thin fireproof partitions... ..........ceceeeees 351 
Expanded metal furring in fiteproofsbulldings, <2 er.naseres s reietey ecw ae te 3504 
Expanded metal systems of floor Construotionn vin. meres tales ocie eoe ole soe oat 406 
Pelton’s system of reléased/ashlariy fc.u ces! lsat ste sie hen tae ee wale a enue Le 
Preventing stains in ‘plastering. 7 (te ssmiee beni cere os siete wietors iotatsiain's a lave se 403 
Roebling's fireproof. floor, weightand:strenpth, Ot. aye. de e's e's as oie sorely wet 404 
Stain, and damp-proofing-—Antihydriné? yam os iaev ee spies ovina on tee seiy 403 
Terra, Blanca fireproof tilingy.”5 20 es ie other as aid teat satya een pase dO 
Thin fireproof partitions, door and window frames in... ......++oeeeeeeees 351 
Weight and strength of the Roebling fireproof floori 7. ss. ceeesws ecls ves. 404 


INDEX. 


A 
Actual weight of fireproof floors.... 290 
Adhesion of mortars to brick and 
GEOL Gotenaieiadetstel siecle ciselsl sielere «ens tole II5 
Advantages of hard wall plasters... 339 
“+ metal lathing das. 325 
PGI Tl SOOPTAi ye cece dat dee ors kate re 116 
American marbles, description of.. 129 
“ Portland: cement... ns. <t 104 
ee sandstones....... emcee pal Se 
rh Slaice we. aks aaaiets com 
Analysis of natural cements. . eo OL 
Anchoring walls to floor joist. . 2217 
Arches, brick, 236; centres for, 173; 
elliptical, 171; flat, stone, 172; 
floor, 262; inverted,’ in founda- 
tions, 67; relieving beams over, 
PFO Arup ple. 173 Stone wi). Gi 107, 170 
PATEL LISS: 12 ere teig stores ace Pert rele 76 
PA YCAS) SIOTIG INl .ss afew aia =o i's\e 6 bis 82 
‘| window and entrance ?...<: 81 


Ashlar, backing of, 179; description 
Gi ssi ents 3s Sine > Olt rT 7; 
specifications for, 376; thickness 
of, 177; tying and bonding...... 178 


ASplialt go. lie Sire Vs.ccackeese's.s PH 
Atmospheric action on stones..... 142 
B 
Backine Olewone mrchesen sss tases: 170 
Backingvolstone ashlar ass o.:% 4s vs 177. 
Patteearus aren tase Gears ol eteras ots ie 
Bay windows, supports........305, 311 
Bearing power of soils......... LO; 420 
Bienstiales sce ar. as sal atee wie sie ais 134 
Bond in-sbrick works sisi ces cc 0 ci 214 

‘© “stones and templates........ 180 
EPP LIE DCES rue cit Win aaa tielele Os 225 
BGNOMe OF GSA Gates vie ards aa) apo £77 
“ Wbrick arches, ., aiss\« 0601295 
ut eve HOlow) Walls: cos «5 ase 230 
ss ** stone foundation walls.. 70 
Bostwick steel lath. . sarge 325 
Bracing the walls of buildings Bea gi 
BSPIGU APC RES Grea at ee cee iets rae 235 
SP CHIAING VS apres akar sek tte nena 5 C 


EY VCOTHICES yas s 2.6%. 


SSL GOURIPE Sice'a «1c bt sincus ca ege eat OS 
Gee MA la etna am ecbed oreo Sieve sip 05 
Sem HOPE: cs carn o vies ees 0 wa) 250 
RIOR WAIVER Shetek peach te ware oe cal eta Goy. 


¢s “veneer construction. ....«.... 233 
‘* walls, construction of........ 214 


COC RON WW MCE CRE US 233} 210 | 


Bricks, advantages of, 189; color 
of, 202; composition of, 189; man- 
ufacture of, 190;. requisites of 
good, 203; size and weight of, 202; 
specifications for, 378; strength of, 204 

Bricks, classes of: arch, 201; dry 
pressed, 194, 201; enameled, 197; 
fire, 200% glazed, §197;. hand- 
made, 190; machine-made com- 


mon, I9I; paving, 199; salmon, 
201; soft mud, 191; stiff mud, 
192; stock.. . 201 


Brickwork, 204; “grouting, 206; ‘lay- 
ing, 205, 207; laying in freezing 
weather, 208; measurement of, 
246; ornamental, 209; specifica- 
tions for, 377; striking the joints, 
206; thickness of joints, 205; wet- 
ting the bricks, 208; efflorescence 
on, 243; strength of....245, 399, 400 

Briquettes, cement for testing...... 107 

Broken ashlar se om cee whe os ste eee 153 


Building stones, absorption of, 147; 
color of, 140; durability of, 141; 
hardness and strength, 144; meth- 
od of finishing, 144; oxidation of, 
143; protection and preservation 
of, 148; resistance to. fire, 145; 
seasoning of, 148; selection of, 
139, 145; solution, 143; testing.. 146 

Buildings, staking Outal. Viiv, «). « 13 

Buildings, stone, list of........... 395 

Burning bricks, see also kilns...... 195 


Byrkit-Hall sheathing lath........ 319 
Cc 
Caissons, for foundations........¢. 57 


Capping of piles, concrete, 393 gran- 
ite, 39; grillage.......... pe ge AC 


Wear OlepeliC Mie waae wee eects saan a 344 
Cast iron ALC VITCETR) .tasy vis a) 5 vletara SOF 
chimney caps. . 316 

: coal hole covers. ie sein, G10 

“ door ouards..... Deseo is 

es Habel ies ies. ROR iia were GOR 

ie SKOWDACKE elec atari > a15 
Celings sTEprool 4 aah en se <eee s 203 
Cellar walls, dampness in......... 8a 


Cellars, making waterproof.. ..... 401 
Cement, Fort Scott, 100; Keene’s, 
343; Lafarge, 111; Louisville; 100; 


416 
Milwaukee, 100; Portland, 103; 
Roman, 103; Rosendale, 100; 
Utica pace ee ee eee ee 100 


Cement mortars, data for estimating, 
114; proportion and mixing, I12; 
specifications for, 375, 379: 
strength of, 113, 115, 400; use.. III 

Cementewa lke ss otc cece nes 85, 368 

as WallPlastersi se score: sp es 336 

Cements, natural, analysis of, Io; 
characteristics of, 102; how made, 
distribution and varieties of, 99; 


testing. Wess -cisiee 6 vaner ss 102 
Centres for erches: nen Ss atiees's ee LTS 
Chemical Walbsplasters, .Giccs sea 1s 55 30 
Chimney caps.of Cast tr0ta..5 a2 mien glo 


Chimmeys, construction of./.)...,. > +0230 


CIA VESOUIS a eras test ee Ane ae 17 

Cleaning down brickwork..... 243, 381 

4 stonework.s.. 2203904 TF 

Coal -hole*covers’: one ctenss eee SEN SS 

COlOTvOr WOrickS Sy ro wesc oats tener 202 

SS eei (OUULGING TSCONES cat lcteniert: 140 

“<] natural CementS.., ss.ceae LO 

se. -rortiand ‘cements... osc. 105 

Coloréd mortars sean er ee awe t eases 

Columbian fireproof floors......... 287 

Column casings, fireproof... ...294, 295 
Concrete, characteristics of, 118; 


data for estimating, 122; deposit- 

ing, 121; materials for, mixing, 

119; proportions for, 120; specifi- 

cations for, 373; strength of..121, 
366, 400 

Concrete and tension bar footings, 
42° HOOrsi rcs chev Nae et 279 


Ry building construction, 357; 
details of, 363; examples of, 358; 
expansion and contraction, 367; 
surface: finish a2 ss supe ie oreo 364 

Concrete capping for piles........ 39 
floor -construction. ...5... 273 
footings 2. cto senna a eraiae OS 
MIXING Machinesses was 366 
ty sidewalks, 85; monolithic, 368 
= for monolithic construction, 365 
Connecticut brownstone.......... 132 
Construction of brick walls, 214; 
anchoring, 217; bond, 214; cor- 
beling for floor joist, 220; damp- 
proof courses, 227; hollow walls, 
229, 232; thickness of walls, 223, 225 
Construction of chimneys. . 335 
fs of concrete buildings, 


6é 


66 


358, 363 

ss ol fireplaces 7 eae 
Corbeling brick walls for floor joist, 220 
Cormites britletiev ro. wettie e 210 


66 


plaster, 341; terra cotta 


erounds forv. eaon oe: Pa ga So Petia 351 | 








DLV LIE, 


Cost of concrete, 122; monolithic 
CONSETUCTION 27.2 ssa ios Astaeisie 361, 363 
Cost of metal lathing...... shes euetots 355 
“plastering and. stucco...).61 355 
SB EStAll sek htea teente Gee dele thes 4O 
CLACKSIIM Walls, +5 viens alec ca leneees 226 
Crandall, for cutting stone......... 156 
Curtain walls: eo dixie. a a 225 

Cut stonework, 150, 188; specifica- 
tons ford warca a oe Nee ee 376 
CULE BOM PILES fixe rasan arta ais creer 39 

D 

Dampness in cellar walls, how to 
prevents Ans. aoe aie ee eee cree 80 
Datnp-proof,courses.j0. «mie ene 227 

Damp-proofing brick and_ stone 
Walls Groh ices dots res Peeme cane Wes emery e 
Dense hollow tiling, t..0eies eo nee Zor 


Description of granites...... 
oe limestones stresses es 27 


“s marbles.?.;..cpute eee vk 20 

oa sandstones...... veh 

ef slates.. vas wate oy, 
Diaper work in brickiy. 524s Pies 
Distribution Of PTANILES @.70 3 AS aes! 
limestones: thiite es as tl 27 

Ps marblesedeeecet. antao 

ce natural cements.... 99 

as sandstones ...:.... on Kei) 

a SIACTES Says ceuietare ses 136 

Door bumpers and guards, cast iron, 316 
Durability of building stones...... I4I 


6 


concrete buildings. ... 
iron in concrete...... 42 
iMG AHOTtary.. sev. vie oe QO 


‘6 


6c 


es COLTAN COUR te clue cretere oe oie 
E 
Effect of atmosphere on building 
SCOMESitoca set etere here etyeas dhe seach sae 142 
Effect of climate on stones........ 140 


oe 


heat on building stones .. 
‘¢ heat and cold on building 
SCONES ols, ss ceete ts aioe aremalcnever del crease 1 
Efflorescence on brickwork . 
Elliptical stone arches a tas. seemed 71 
Enameled bricks ...:..... Sse aah 197 
End-method hollow tile floor arches, 265 
Estimating the cost of concrete.... 122 
‘* quantities of mate- 
rials required in mortar......... 114 
Examples of concrete buildings. ... 
Excavation, specifications for, 372; 
staking out for, 13; Rie 
SHCELOL, Fees cle Se ete e ote 29 
Expanded metal lathe ey oa 
Expansion and contraction of ce- 
Ment Mortars. as. ers eC eR LLG 


398 


INDEX. 


Expansion and contraction of con- 
ChGtR on yt = voxels & 6s Ga ae ohh ose 367 


External plastering........ - 344 
F 

Fawcett fireproof floor... ......... 279 
Pibredos plaster...... plekarere ive’ sare 329 
BMC e aN RE CE I ha sss c <hols vie's 9 n't 0: 344 
SURERHTEC Cbaniter ets cera ieee eo via, a's © 200 
PAPEPMACES oF cious s0.0ipie & vice o's as ox 242 
Fireproof ceilings... 293 

ss PLUMES Hence ware gin eee erat 262 

re POOLS Oe ser ere che sree Be 292 


? VUILS* ye ec eres 
Fireproofing: by ‘whom it should 
be done, 258; floor construction, 
262; girder and column casings, 
294; partitions, 297; roofs, 292; 
selection of a system of, 291; spec- 


ifications for, 382; wall furring. . 299 
Fireproofing materials: clay ok 
ducts, 260; concrete.. 202 


Flat arches, brick, AG Re stone. . Aa See 
Floor arches, see floor poneirichcn: 262 
Floor construction, 262; Columbian 
floor, 287; concrete and metal 
floors, 278; Fawcett floor, 276; 
floor and ceiling~ finish, 271; 
Guastavino floor, 275; hollow tile 
floors, flat, 263; segmental, 272; 
Metropolitan floor, 282; protec- 
tion of, 270; Roebling floor, 284; 
setting, 2097 /tie-rods:...... 270, 
Footings, centre of pressure in, 26; 
computing the weight on, 23; ex- 
ample, 24; inverted arch for, 67; 


274 


PIOPORUIONING tatecue gfe aa minieseis' srs 22 
TOGOEIN OS, TICK, ce tislen's e's o's wage! 65 
He concrete, 62; specifica- 
FAOUSMIOT Ee en eat cee ove 373 
Footings, concrete, withtension bar, 42 
ss MEAS OIE Cr ateres oi ah dig.sj6: cic se 

ae steel beam.. Pre eA 
es stone.. : ab Ga: a 
es timber . “cs eet! 52 


Foundations: caisson, 57: Chicago 
practice, Olp: continuous, 22; 
depth of, 17, 21; designing of, 
21; pile, 31; spread, 44; superin- 
tendence of, 29, 77; underpin- 
ning of, 88. See also footings. 

Foundations for World’s Fair build- 


TAGs Siecle Sea tet Cee at Gia an 54 
Foundations of the City Hall, Kan- 

SOS ALY ee aisiny tee so Se wee ars 55 
Foundations of the Manhattan Life 

Building, New Yorks: ..oi.0 57 
Foundations of the new Stock Ex- 

change, Giicapph enim odes ne 56 


Foundations on compressible soils.. 31 





417 


Foundation walls, 69; specifications 
for, 374; stone, bonding, 70; fill- 


ing of voids, 72; superintendence 

Gley AetiieKness: OF:%', sive woaces 79 
Freestone, see also sandstone...... 131 
PLECrMgVOlMOTAL: ots ais. «ves < 6 117 
Partin blocks ons yc eet sc o's oatve 252 
mre tor Walls: tiie, sects es betas 299 


Furring for wire lathing. .321, 350, 388 


G 
Georgia marblese.s.cy..; 129, 392, 394 
Girder casings, -fireproot isi. cas es 204 
MITA AOI Ma GU Ce at Seat aaa. yey anne 197 
Gneiss, see also granite...... Sie artes 
Granite, characteristics of, 124; 
chemical composition of, 393; dis- 
tribution of, 125; effect of heat 

on, 125, 398; strength of, 391, 

400; weight of.. MPC agae SR 
Granite capping for piles. Oy start ate ters 39 
STA VEL ISOUIS: Cette sw tier Ain wteia alee es 1 18 
Cnlave On Dues een «- «esse ese 0) 40 
ST OUMUS penis avers acre eee Wiha 324, 339 
CPOE ips atc les ctdteroleae eg causa 114 
Gudstavino iicorlarch 40. <4 2 ses. 275 

H 
Pigiy TOreplAStering i. wc sae} =.= > 329 


Hammond metal furring, ....\.45.. 321 
Hard wall plasters, 335; advantages 
of, 339; application of, 338; ce- 
ment plasters, 336; chemical plas- 
ters, 337; how sold, 338; specifi- 
CATION SELOPS Ge ab ltesic.s cece ee 387 
Hollow tile, 260; ceilings, 293; 
floor arches, 263; partitions, 297; 


TOOTS 202) Wall TUTTINg.) oss 6 < 200 
Hollow Walist yo a sc «i <tes vtec 225, 232 
Hoop iron bond....... chencedeees BET 

I 
Invitation warpless 2... res saws © 343 


Inverted arches in foundations, 67; 
AMO AIOUS, LOT co) ae tines oto) 08% te 
From supports Lor lintels, was «oe van 164 
Iron supports for mason work, 301; 
cast iron arch girders, 303; cast 
iron lintels, 302; supports for bay 
windows, 305, 311; wall supports 
in skeleton construction......... 307 
Ironwork: Bearing plates, 312; 
chimney caps, 316; coal hole rings 
and covers, 316; door guards, 313; 
GREWDACKSMc ts onic ted tc amt «oo 312 


J 


Joining new brick walls to old..... 222 
AGintSanashlars cs. dauiise les sacs ak 70 


418 

Joints in brickwork, thickness of... 205 

J OINES OBLIPs nisins wile abe ia lela ein serene 180 

Joist Hanversss «6 eae tenses 219 
K 

Keene's cement, sins. ssitiaeicis cnercrs 343 


Kilns for burning bricks: continu- 


ous, 197; down-draft, 196; up- 
CEAI Cs oc sete chaale Sten eh lene feet 195 
L 
(ia bel MOuUldingsis <i elc sis ser ee TOO 
TLahar pence mmeals shaw Me avin atr er ri 


Lathing, 318; in fireproof construc- 

tion, 350, 388; specifications for, 
386, 388, 389 

Laths: Bostwick lath, 325, 389; 

Byrkit-Hall sheathing lath, 319; 

expanded metal lath, 324; sheet 

metal laths, 324; wire laths, 320, 
383", wvouden lathsir. wesley eet a oe 319 
Lava Stone. Secs ais thes erties Bure real oa 


Laying bricks, 205; in freezing 
weather.. : : 2 208,392 

Laying out stone ashlar........... 177 

Laying out stonework Jo. 5.0. alae = 162 


Lee hollow tile and cable rod floor.. 281 
Lime, characteristics of, 94; how 
sold, 93; hydraulic, 97; impuri- 
ties'"in,) 103” | nature Vor, 13:4 pre- 
serving, 96; slaking and making 
into mortar, 94; weight of...... II4 
Lime and cement mortar. deere td 
Lime mortar,. brick dust | in, 99; 
durability of, 96; how made, 94; 
proportions af 94; setting of, 96; 


white and Coloredin) diese tren eat 95 
Lime <plasten say tino). ete ais cie sete 327 
Lime putty.. OO 


Limestone, characteristics ae 126; 
chemical composition of, 393; de- 
scription: Mof~ American, 7.127. 
strength of, 39I, 400; varieties 
Of 4.127) WVEISDiNOL. § erie sr atsle SOL 

Lintels, relieving and supporting... 164 

List of stone buildings in the United 


States 3:8, man piers vai ceeretenaaentens 395 
Loam and made land... ieee es 19 
M 
Machine-made mortar...........- 330 

Manufacture of bricks: by dry, clay 
process, 194; by hand, 190; by 
soft mud process, I91; by stiff 
mud process, 192; drying and 


burning,’ 195; repressing. 7. 29193 
Manufacture of terra cotta........ 249 
Marble, characteristics of, 128; 

chemical composition of, 394; de- 


INDEX. 


scription of American, 129; 
strength of, 392, 400; weight of, 392 


Marbles imitation aa nc. sea cls. eee 343 
Masonry, see stonework, safe work- 
imi loads for yj (Aratas Se otek 'e's 9 400 


Masonry wells for foundations..... 55 


Measuring brickwork... J./4....<+0. 240 
ba. plaster work.... 354 
us StOnNeEWOER encod as anos ik 185 
Metal laths, see also lathing....... 320 
Metal furring for wire lath, 321; 
SPECIICALONS MOPes satu uyet as nen SOO 
Metropolitan fireproof floor....... 282 
Mixing colored mortan..> 4 -or cee 123 
+S 0) CONCTCLE a shia ven ates eee I1g, 365 
‘* mortar for plastering...... 329 
Mortar, cement: proportions and 
mixing, 112; specifications for, 
3752370 ,sereneth Or, 123, 11s, 
AOD PAIGE Se nvacin sien tens «206 eet are Lit 
Mortary colored fase: cate oareey cranes 95 
Mortar, lime, durability of, 96; 
machine-made, 330; mixing of, 
94; proportions of, 94; specifica- 
HlOnSHOP ae TU Ase eter eee iach 379 
Mortar, lime and cement, mixed... I14 
‘* Rosendale and Portland ce- 
WEIS MHIKOd Aiea heey wee eee ba fect 
Mortar-adhesion of as. sais eee I15 


“ce 


change of volume in setting 118 
data for estimating cost of.. 115 


‘tira fOr DMCKWOrke santana ware 205 
“for plastering...........:. 329 
Rome HEOEZING Ol art causes «tee L7 
Sa plaster OlRP aris: ini... nie ae 116 


safe crushing strength of.. 400 
ealtdiiin ssiocie ccc ee oe rete ED 


SUPALIN = tees Lae) 
“sto” iinake- eee to 
WALCLGA vate hata LO 


Mortar colors and ‘stains: Shines: 


use, objections to, 122; mixing. . 123 
Molde bricks: elie. ane. snee 210 


Natural cements. .:........%90, 101, 162 
Nature ot soile sn. 605 alee ee ene 14 
Needling walls and foundations.... 87 


O 
Ohio Stones). eas uses. omse ene EE SS 
Onyx marbles. 5 ‘sy. 0c saree 130, 395 
Openings iniwallsetoee see ioyazak 


Ornamental brickwork, 209; cor- 
nices, 210; surface patterns..... 212 


Pp 


Paintin® stonework, sc seam ee oe 148 
Partitions, ‘hollow: tile. 2% -asss. sean 207 


LIVI LEX: 


Partitions, thin solid: of metal, 351; 


CHNCUON es ichwa ee dors ee eee ok 299 
Party walls, thickness of...... ae ce aes 
Pavements, cement, 85; stone..... 84 
Paving riche s.s ate sew tga sl 199 


Paving, brick, specifications for.... 382 
Peach bottom slatewc a. vn. erica ees 198 
Pile foundations, 31; objections to, 41 
Piles, actual loads on, 38; bearing 
power of, 35; classes of, 31; cut- 
ting off and capping, 39; Zgi- 
neering JVews formula for, 35; 
experiments on, 36; manner of 
driving) 33, materials~ for, 32: 
municipal regulations, 36; point- 
ing and ringing, 32; spacing of, 
33°; Specifications fOr. 9. wr... sate 375 
Plaster: lime, 327; hard wall, 335; 
machine-made, 330. See also 
plastering. 
Plaster COMmICeS actdnaerce ict ae ernie 341 
Plaster of Paris, 340; in lime mortar, 116 
Plastering, materials for, 327; mix- 
ing, 329; putting on, 332; speci- 
fications for, 386; superintend- 
ence of, 352; with hard wall 
Dlasters, octets estes te ss 335 
Plastering Cost Of tet t ate lend'2 355 
Plastering, external: rough cast, 
SLASSIAL MAT St UCCOm ene cc 346 
Plastering in fireproof construction.. 350 
Pointing Stonework gnc var dans ashes el Oe 
Porous hollow tiling y...-¢22 <a. < + 260 
Portland and Rosendale cements, 
TIK GU Spano picts tera gerate 113 
Portland cement, 103; activity and 
weight, 106; American, 104; 
color, 105; firmness and sound- 
ness, 107; specifications for, I1I; 
strength of, 107, I10, III; pore 105 
BOZPUOIANASC facts o sores . 98 
Preservation of stonework: by oil, 
149; by painting, 148; by Ran- 


SOMES PROCESS 25 5 oer sst ens <towia ee ehs 149 
Pressed bricks, 201; manufacture 
of, 194; moulded and arch...... 202 


Proportions of materials: in con- 
crete, 120, 358, 363; in lime mor- 
tar, 94; for plastering, 331;. in 
Portland and Rosendale cement 


WIGTLSTS np scene dere aia iste sreie Pee nl ro 
Proportions of sand and cement in 
mortar. ‘s vith al 9 
Protection of floor arches.. Vakune 270 
os of stonework.......148, 182 
Q 


Quantities of materials required in 
concrete, 122; in mortars, I14; 
in wall plastenenews<piee x slae hao 332 





419 
Quoins-and jambs.......... vaecad 155 
R 
Ransome & Smith floor.. San pert TO) 
Relieving and supporting lintels. ees lud 

gh arches and lintels....... 237 
ne beams over arches....... 170 
Requisites of good bricks......... 203 
Retaining walls, proportions for.... 74 
Rock foundation beds............ 16 
Roebling fireproof floor........... 284 
PL Oua WSL OLeli te ai aataik <5 ee wis fc ahs 103 
TeOOES |. MPEPLOOEs ca. Nas esc ia cl aetalehole os 292 
Roush cast plasteriny 14... . o's. + « 344 
Rubble arches. . fa sk 

Rubble work,. description « ‘of, 150; 
measurement of. PA eo Senne A 24 

> 

Alt I MOT ARs ok eeu aera s Tr7; 382 
Sand as a foundation bed......... 18 


eé 


finish, 335; specifications for, 386 
fOr mortar, testing; Cte. Was. 05 
for plastering mortar........ 328 
Sandstones, 131; composition of, 


«6 


sé 


131, 393; distribution of, 132; 

properties of, 132; strength of, 

392, 400; weight Of a a eee 392 
Scagliola . . siiscsh.coheae. puncte create i 42k 
Screeds in plastering. sreteian Ss Sateeanetle 333 
Seasoning of stone. icoste arn n AS 


Segmental floor arches: .* see 272 
Selection of building stones ...139, 145 
Setting cut stone, 181; specifications 
for: Me ew 
Setting hollow tile floor arches, flat, 
269; segmental, 275; specifica- 


ONS OTP, axe tet. et Serenade eos 
Setting terra cotta, 254; specifica- 
PIONS Ober doe on con eet oF 385 
DOU Ol CEMENL Ni «0 els wad 00x 100 
SOU MMe MOM aL oa ais Old 96 
Shale, blue.. Boag ari bod 
Shoring up of buildings. . . 86 
Side-method hollow tile floor arches 263 
Sidewalk vaults.. Pa 83 
Sidewalks, ferent 85; concrete) 
Monolithic. 308% stonelae xb. sets 84 
PaU His ere) Up easiahar aietnts nets acy “enisretats auntaciat 166 
‘« stone, cutting and setting.... 166 
SIZE DITACKS. sa Se dapat aims ay wae © 202 
Skeleton construction, details of 
Walle SHPPOLiG.2 «= wralcsig «pee 00.5. n 307 
Skim coat.. : » 334 


Slate, 135; absorption, market “qual- 
ities and uses of, 136; color, 136; 
constituents of, 135, 395; distri- 
bution of, 136; hardness of, 135; 
tests for, 135, 136; weight and 
strength Of.....eesseeeeess 135, 393 


420 

Sip jomtsana s.r. te HOO 180 
Slip Sills. sie sca eave atentpenenes ele os 166 
Soapstone, nature and uses of..... 139 
Soft mud {brick¢27 5 su. aso oe IgI 


Soils, actual loads on, 20; ‘bearing 
power of, 19, 20, borings in, 15; 
NAtUPe"Ol own hat ee es ee ee 14 

Soils, kinds of: clay, 17; compress- 
ible, 31; gravel, 18; loam and 
made land, 19; mud and silt, 19; 
COCK wi 1G Sand on at Ree aa 

SPanarelssupportssws oe oe sale 308 

Spandrels over stone arches........ I71 


Specifications for brick paving..... 382 
a brickwork. . Beli 
. concrete footings, 373 
st cut stonework... 376 
1 excavating and 
PTACING,..v s/o es kk Co he 
Specifications for fireproofing...... 382 
Es PTAMILES. oa. ese 376 
J, lathing and plas- 
TETIN Go :018 EN Bieter bn, eateedelah ees oa 386 
Specifications for laying masonry in 
freezing weather aainnres act om 382 
Specifications for metal furring.... 388 


mortar for bricks 

work, 379; for fireproofing, 383; 
for. stONCWOrK-ave «cis See Sar sin ee 375 
Specifications for piling. . se 
Portland cement:. cg 


a Roebling fireproof 
floors. fat 1 aateatnoeietee cosine tate 390 
Specifications for setting stonework, 377 
He stonework. ise 374 

- terra cotta trim- 
mings. ne . 385 
Specifications for thin. paz titions. . 389 
wire lathing..... 388 
Spread foundationss.: scores eee 42 
DOCAEE os, ct an elements eater eae eee 347 
Staining of plastered ceilings...... 270 
Stairs, SONG ieee n ak are cae eee 176 
Staking out ‘buildings. asaee os 13 


Steel beam footings, 44; calcula- 
tions, 47; manner of using, 45; pro- 
tection from rust, 46; under piers, 50 

Steel supports for mason work, see 


also iron supports. . . 301 
stiif mud brickgeetens oe 192 
Stonecutting and sara See 155 
Stonecutting tools. 155 
Stone footings, 63; ‘bedding, 643 

Offsets forisd «+ : 64 
Stone foundation Cie Bee PES charger A 70 
Stone pavements, (2.0. se eae eed 
Stone, seasoning Of ate e nse 148 
Stone, ‘set. on hed: ons oe 142 


stone steps and staifsio.v si. e0e ost 
Stone trimmings... 














INDEX, 


Stonework: arches, 167, 170; ash: 
lar, 151; cleaning down, 183; 
defects in, 186; finish of, 158; 
laying out, 162; measurement of, 
185; patching, 187; pointing and 
protecting, 182; rubble, 150; set- 
ting of, 181; specifications for, 


374; superintendence of, 186; 
trimmings, 155, cts working 
strength of.. ris «kt aera O 
Stones, building. . caine 30 
Strength of brick piers, a actual. eae 399 
bricks.. eae emirirtte LOA 
“ brickwork .. Rie Skettis 244, 400 
Ss concrete,@......121, 400; 400 
f flat flooriarches:, . 4... 5.274 
$e BTANILES, vo Ginjneiee A GOLy AOC 
a ALON 0: hte Saisie a Mieco eae 401 
limestones .5.gs.5 = 3 391, 400 
es Marples ce. cre 392, 400 
iy ANIOHUATS  rerecckapeterenene I15, 400 
Ss Portland cement...107, 
PIO, 1 DE 
% Portland cement mor- 
LATS Bia cre Choe sicte store Savane aise BE. eS 
Strength of Rosendale cement...... 103. 
zs sandstones teas ae 392, 400 
a segmental floor arches.. 274 
oe Slates. cc Cott tei oes 393 
44 steely sic 0a itis Suiste cck eet 401 
of stone columns and ma- 
SOHTY 5 AR oo ee cr keene ciel 183 
Strength ofstone lintels: 7. <.s.schee 184 
td LEITA COLEE Taeclns wana 257 
ai timbers. aes duvet ee 401 
Stucco work, 340; for external plas- 
tering, 346; fibrous plaster...... 344 
SUSSE AN MOLAR. fe sense) om Slot sine TE, 
Superintendence of brickwork.. 7247 
concrete work... 
77, 366 
EXCAVALIONS gst,. 229 
he footings and 
foundation walls... sade coo eee 77 
Superintendence of lathing and 
plastering .. vse S52 
Superintendence of stonework. .... 186 
Surface patterns in brick.. 252 
Syenite, see also granite. .3 sae. 125 
T 
‘Vemplates, Stone eo yerens. . eee 180 
Tennessee marble. <<... ose ee 129 
Terra cotta, architectural: color, 
250; composition and manufac- 


ture, 251; durability of, 251; ex- - 
amples of construction, 253; lay- 
ing out, 251; setting and point- 
ing, 254; specifications for, 385; 


INDEX. 


use of, 251; weight and strength 

eee ee ds tine Me sddaetes sf 257 
Terra cotta grounds for cornices... 351 
Testing building stones, 146; by 


acid, absorption and _ fracture, 

147; by compactness, 146; by 
ROUTAN ote aver he wancwisiniets Oates x0. 148 
Testing natural 'cements:.......... 102 
(a Portland cements... 7: %-, 105 
‘* soils, for bearing power, I5, 20 
Thickness of brick walls...... 2225-095 
A foundation walls..... 73 

- joints in’ brickwork, 
BibT SLORE MOL ye stot ee leeee wee 179 

Thin partitions: metal, 351; tile, 
200) SpeCLications LOT aan ees 389 
sbying walls at @ngles secs !qiuvies 221 
Tie-rods for floor arches...... 270, 27a 

Timber footings, 52; calculations 
for’ 54 


Timber foundations for temporary 
buildings ......... iagero isha xreye st 52 

Tools for stonecutting. . Puteri P55 

pL TEDISLONG ar Reva raale sinhads wid s atiese = 8 134 
rimmings, stone: columns, 174; 
copings, entablatures:....... «+ 175 


U 
Underpinning foundation walls, 88; 
Chicago practice....... hole. cars <i: gI 
‘V 
Waultawalle:-csictrtese Se ee ees ATO 
Vat Sue leet svehes ers otete a! wee orece te 237 


fireproof... .0scscseee eves. 300 





421 


Vaults under sidewalks and steps... 83 
Veneer consiruction.’... ue ac esse | 233 
Vermont marhiay che. ve cs at bole a nae lo 


AVY HS NOUNS sete aie die <i a9 Ware fos Sie 218 
Wall furring, tile. . xt 290 
Wall supports in skeleton construc- 


LOU ea he Seri ice Vansak Eek oe 307 
Wralltiedrataes© tay ates 215, DAT 239 
Walls: area, 76; foundation, 69; 

retaining, 74; thickness of, 73, 

so DEMONTE yore Ghat ata ce oe eo opie eae 76 
Waterproofing CGATS pone ts wiciy «5 401 

te brick and stonework, 243 
WVelgDT-Of DTIEK Sac Sah ctcr. wins sehen. 202 
3S SPPAMILCMs tw eFao de atea th n= 391 

o hollow tile floor arches: 

Hat; 267) segmental yc. oh eis o1 274 

Weight OPUS me se See var cians thane 114 
GIMESLONES he eieist a ee » 391 

4 POAT OLGA ey. ns ores x eet Oe 

os natural cement 3 a ecto 102 

si ONYX MAL DIESy gen sls. eie wie 395 

as Portland cement........ 106 

se SANCASUGUES s 4\)5.c. 0 cfaie cheese 392 

AY SALE Ra tov als an stare rca 405 

aa terra: COLA Gato saels cea 257 
Woettioe Bricks... 20.5 <wshtauh lO, 205 
Wiite COAtC oa ims 54 tote ce Pepe ke ASR 
WY Ritewashing shee foc hows wee os 349 
Window and entrance areas....... 8I 


Wire lathing, 320; specifications for, 388 
Withes in Chimneys. .% 4). ns vise e's « 240 
AVG ei wallsa nient..ctcala caters ihe 225 
WVOGCERADIICKES 2 vc as ws velesaix'as es 4.220 





ADVERTISEMENTS. 


It is believed that the advertisements on the following pages will 
be found convenient for reference by Architects and Builders. All 
of the materials or parties represented can be heartily commended 
by the Author. 





ADVERTISEMENTS. 1 








OVER | 4 veEars 





STANDS HIGHEST 





REQUIREMENTS 
OVER 1,000,000 BARRELS 
USED ON 


NATIONAL, MUNICIPAL & RAILROAD IMPROVEMENTS 


THE LAWRENCE CEMENT C0. 
Sales Office. No. 1 Broadway, N. Y. 


E. R ACKERTIIAN, President 
Assoc. Am. Soc. C. E. 


Philadelphia Office, L. V. Clark, Harrison Building 


il ADVERTISEMENTS. 





Sloe A UeBRULE DING: George B.. Post, Architect 
HAVEMEYER STORES, George B. Post, Architect 
EQUITABLE BUILDING, George B. Post, Architect 
WELD ESTATE BUILDING, George BP. Post, Architect 
COE ESTATE BUILDING, George B. Post, Architect 
THE PARK BUILDING, George B. Post, Architect 
EMPIRE BUILDING, Kimball & Thompson, Architects 
STANDARD OIL BUILDING, Kimball & Thompson, Architects 
SHERRY BUILDING, McKim, Mead & White, Architects 
N. Y. LIFE INS. BUILDING, McKim, Mead & White, Architects 
UNIVERSITY CLUB, McKim, Mead & White, Architects 


EXCHANGE COURT BUILDING, Clinton & Russell, Architects 
METRO’N LIFE INS. BUILDING, N. LeBrun & Son, Architects 


ATL. Portland 


Cement 


GUARANTEED TO BE SUPERIOR TO ANY 
IMPORTED. OR DOMESTIC. CEMENT ese: 


ATLAS PORTLAND CEMENT CO. 


30 Broad Street, New York, 





AMERICAN SURETY BUILDING, Bruce Price, Architect 
RESIDENCE GEO. J. GOULD, ESQ., Bruce Price, Architect 
SINGER BUILDING, Ernest Flagg, Architect 
MILLS SHO TEES sen osmisandse, Ernest Flagg, Architect 
SCRIBNER BUILDING, Ernest Flagg, Architect 
JOHNSTON BUILDING, J. B. Baker, Architect 
PRESBYTERIAN BUILDING, J. B. Baker, Architect 
BANK OF COMMERCE, J. B. Baker, Architect 
GILLENDER BUILDING, Berg & Clark, Architects 
HARTFORD FIRE INS. B’D’G, Cady, Berg & See, Architects 
TOWNSEND BUILDING, Cyrus L. W. Eidlitz, Architect 


FIDELITY & CASUALTY B’D’G, Cyrus L. W. Eidlitz, Architect 
WASHINGTON LIFE B’D’G, Cyrus L. W. Ejidlitz, Architect 


ADVERTISEMENTS. ili 


NATIONAL — 
FIRE PROOFING 
COMPANY 


MANUFACTURERS AND CONTRACTORS 


Hollow, Porous and Dense 
Fire Proofing Material. 


Long Span System of Tile Construction, 
Effecting Large Saving in Cost of Steel, 


OFFICES : 


Frick Building, Pittsburg, Pa. 
806 Hartford Building, Chicago, III. 
170 Broadway, New York, N. Y. 
North American Building, Philadelphia, Pa. 
Tremont Building, Boston, Mass. 
Canton, Ohio. |: 


1V ADVERTISEMENTS. 


THE HINCHMAN-RENTON 
FIREPROOFING CO. 


(INCORPORATED. ) 





Contractors for the <3. 


FIREPROOFING OF BUILDINGS 


CONCRETE CONSTRUCTION 
OF ANY KIND. 


We use more cement per annum, than any other firm 
west of the Missouri River. 


The Hinchman fireproof floor (patented) is absolutely fireproof, 
possesses great strength, with minimum OME ate depth, and can 
be adapted to any building. 


Owing to the great economy of our construction we are prepared 
to compete with any system affording the same strength, and fire re- 


sistance, and especially in the territory west of the Missouri River 
We also have a semi-fireproof construction which is equal to many 
so-called ‘‘fireproof”’ constructions at only about one-half the cost. Per- 
haps this is just what you want. Write us for particulars. 
Plans and estimates cheerfully submitted on application. 


Let us send you our descriptive catalogue, and a list of some of 
the work we have done. 


Address 


Hinchman-Renton Fireproofing Co., 
1815 Arapahoe St., 
DENVER, COLO. 


PL ede LV LS. v 


The Roebling System 


muna Fire-Proof 
Construction 


Developments in 


The Roebling Standard Wire Lath 


with the woven in stiffening rib invariably secures 
the best and most satisfactory results in ornamental 
plaster effects. 


The Roebling Construction Co. 
Catalogue on Application 121 Liberty Street, New York. 


The MORSE WALL TIES 


ARE ENDORSED BY LEADING ARCHITECTS 
THROUGHOUT THE UNITED STATES 


HOLLOW AND VENEER WALLS, 
TERRA COTTA WORK, 
PRESSED BRICK FACINGS, 
ASHLAR, MARBLE, ETC. 


J, B. PRESCOTT & SON.. Manufacturers, WEBSTER, MASS. 


SEND FOR CATALOGUE. 


As BEING MosT EFFICIENT FOR 


Cabot’s Brick Preservative 


Permanently waterproofs brick and sandstone. One coat equal to 
three of Linseed Oil, and never needs renewing. 


Cabot’s Mortar Colors 


Strong, Durable and Cheap. Work easily with the Mortar. 
SAMUEL CABOT, Sole Manufacturer, Boston, Mass, 


Also Manufacturer of Cabot’s Creosote Shingle Stains. 
Cabot’s Sheathing and Deafening “‘Quilt,’’ ete, 


vi ADVERTISEMENTS. 


es 


DUPLEX HANGERS AND POST CAPS. 


The manufacturers of the Duplex Hangers and Post Caps desire to call the atten- 
tion of ARCHITECTS, BUILDERS AND OWNERS to the superior merits of their joist 
hangers, and to their Post Cap, and NEw I-BEAM HANGER. 





THE DUPLEX POST 

an we} Pere Cap, of which one 
. cd ~“ . 

>< < pattern is shown by 

: Fig. 1 is designed to 

secure the most per- 

fect column and gir- 

der connection that it 

is possible to attain. 

The caps are made of 

mild steel, in - four 

-* pieces, and are applied 

with lag screws. They 

Bes form astrong and rigid 

~ . . 

- os bearing for the girder, 
and permit of a con- 
tinuous post through 
two or three stories, 
making an extremely 
rigid construction. 

Our I-BEAM 'HANG- 
ER, shown by Fig. 2, 
is made to meet the 
demand for a first class 
connection for wooden 
joists or girders, fram- 
ed flush into steel I- 
Duplex Four Way Post Cap beams. The hanger is 
made to fit the flange 
of the beam, with am- 


‘ 
/ 


4 

\ 
> 

/ 


/ 
‘ 
‘ 


/ 


’ 

a 

o ; 4 
: t 

! 

1 

J 


/ 
talents) 
‘ 


/ 


# ae 


Sa eeae a} 
¢ 







4 
, 


Ne te Se 


/ 


Wide cna oy ces 


Fig. 1. Duplex Post Cap. 


ple bearing for the joists. 

A % inch hole punched 6 inches from the bottom of the beam will fit any of our 
hangers. The hangers may be used with any I-beam or channel, 8 inches or more 
in depth. 

We also wish to emphasize the 
fact that DUPLEX HANGERS are the 
BEST, STRONGEST AND Most RE- 
LIABLE HANGERS THAT ARE MAN- 
UFACTURED 

Tests made at the Massachusetts 
Institute of Technology, gave the 
COMPARATIVE STRENGTH OF DIF- 
FERENT HANGERS AS FOLLOWS: 





Fig. 2 
Duaplex,ieccccwcess.- Soe ne ea leie tee. ce’ ce camara om are sates 39,550 Ibs. 
SUIrraps Ver. vewe sce Sele ciolta tie so etdectrelciereieceiite -13.750 Ibs. 
Wan DOM Mg oo aci ne tnrecaccss sad cen vce wens mcesm siete 13,300 Ibs. 


Duplex Hangers are carried in stock in the principle cities and can be promptly 
shipped from the factory, when ordered. 

THE Cost OF THE HANGERS, when compared with the additional strength gained, 
is insignificant. 

2,150,000 hangers were sold by us in 1900 and 1901. Write for catalogue. 


THES DUPCERASHANGE RaGg 
CLEVELAND, OHIO. 


ADVERTISEMENTS. vii 


COST OF MIXING QUALITY OF MIXING 
LOWEST. HIGHEST. 


RANSOME 
CONCRETE MIXERS. 


Used on New York Subway. 
Used on New York Custom House. 
Used by New York Dock Department. 


RANSOME CONCRETE MACHINERY CO, 
11 BROADWAY, NEW YORK. 








RANSOME & SMITH COMPANY, 
CONSULTING CONCRETE ENGINEERS, 


11 Broadway, New York, 


PRIN FR FR IRR FR IRR RR RRR st 


Experts in Fire-proof re-enforced concrete for FACTORY BUILDINGS. 


ABERTHAW CONSTRUCTION CO., 
7T EXCHANGE PLACE, BOSTON, MASS. 
CONCRETE ENGINEERS & CONTRACTORS. 


Owners of Ransome Construction Patents in the New England States. 


BYRKIT'S PATENT Sheathing Lath 


- Will make ¢vue and perfect Walls and Ceilings 11 
TAies— | every building where used. Architects and Builders 
SHARES will benefit their clients by using it. Approved by the 
author of this work. See description, page 319. All 
ATEINE “¥ Lumber Dealers can supply it. 











for information, circulars, etc., address 


Lavi "J The Byrkt-Hall Sheathing Lath Co., Chicago, 





ADVERTS PIM LivelS. 


ANTIHYDRINE 


DAMP-PROOF AND STAIN PROOF COATING 


THE ORIGINAL MATERIAL 
FOR MAKING WALLS DAMP- 
PROOF AND STAIN-PROOF. 


Address: ANTIHYDRINE CO. 


New Haven, Conn. 


The Architects’ and Builders’ Pocket Book 


By F. E. KIDDER, 6, E., Ph.D, F. AL A, 


PUBLISHED By 


JOHN WILEY & SONS, 


43 & 45 East 19th Street, m ww New York. 
FOURTEENTH EDITION. 
1656 Pages, 1000 engravings. Morocco. Price $5.00. 


Without question the leading Architects’ and Builders’ ‘‘Hand Book’ in the 
United States, and the best practical work published treating of the strength of 
materials and structures. 


Fe Beanie 
CONSULTING ARCHITECT, 


Structural and Fireproofing Engineer, 


628 FOURTEENTH STREET, DENVER, GOLO, 


Expert advice and assistance on all forms of building construction; 
selection of fireproofing systems, detailing of steel and wooden trusses, 
etc. Prompt attention given to consultations by mail. 
Special prices given when desired. 


During 20 years practice as a consulting Architect, I have rendered 
assistance to leading Architects and Builders, from Main to California. 


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